1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2011, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Debug; use Debug;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Tss; use Exp_Tss;
32 with Exp_Util; use Exp_Util;
33 with Fname; use Fname;
34 with Freeze; use Freeze;
35 with Impunit; use Impunit;
37 with Lib.Load; use Lib.Load;
38 with Lib.Xref; use Lib.Xref;
39 with Namet; use Namet;
40 with Namet.Sp; use Namet.Sp;
41 with Nlists; use Nlists;
42 with Nmake; use Nmake;
44 with Output; use Output;
45 with Restrict; use Restrict;
46 with Rident; use Rident;
47 with Rtsfind; use Rtsfind;
49 with Sem_Aux; use Sem_Aux;
50 with Sem_Cat; use Sem_Cat;
51 with Sem_Ch3; use Sem_Ch3;
52 with Sem_Ch4; use Sem_Ch4;
53 with Sem_Ch6; use Sem_Ch6;
54 with Sem_Ch12; use Sem_Ch12;
55 with Sem_Disp; use Sem_Disp;
56 with Sem_Dist; use Sem_Dist;
57 with Sem_Eval; use Sem_Eval;
58 with Sem_Res; use Sem_Res;
59 with Sem_Util; use Sem_Util;
60 with Sem_Type; use Sem_Type;
61 with Stand; use Stand;
62 with Sinfo; use Sinfo;
63 with Sinfo.CN; use Sinfo.CN;
64 with Snames; use Snames;
65 with Style; use Style;
67 with Targparm; use Targparm;
68 with Tbuild; use Tbuild;
69 with Uintp; use Uintp;
71 package body Sem_Ch8 is
73 ------------------------------------
74 -- Visibility and Name Resolution --
75 ------------------------------------
77 -- This package handles name resolution and the collection of possible
78 -- interpretations for overloaded names, prior to overload resolution.
80 -- Name resolution is the process that establishes a mapping between source
81 -- identifiers and the entities they denote at each point in the program.
82 -- Each entity is represented by a defining occurrence. Each identifier
83 -- that denotes an entity points to the corresponding defining occurrence.
84 -- This is the entity of the applied occurrence. Each occurrence holds
85 -- an index into the names table, where source identifiers are stored.
87 -- Each entry in the names table for an identifier or designator uses the
88 -- Info pointer to hold a link to the currently visible entity that has
89 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
90 -- in package Sem_Util). The visibility is initialized at the beginning of
91 -- semantic processing to make entities in package Standard immediately
92 -- visible. The visibility table is used in a more subtle way when
93 -- compiling subunits (see below).
95 -- Entities that have the same name (i.e. homonyms) are chained. In the
96 -- case of overloaded entities, this chain holds all the possible meanings
97 -- of a given identifier. The process of overload resolution uses type
98 -- information to select from this chain the unique meaning of a given
101 -- Entities are also chained in their scope, through the Next_Entity link.
102 -- As a consequence, the name space is organized as a sparse matrix, where
103 -- each row corresponds to a scope, and each column to a source identifier.
104 -- Open scopes, that is to say scopes currently being compiled, have their
105 -- corresponding rows of entities in order, innermost scope first.
107 -- The scopes of packages that are mentioned in context clauses appear in
108 -- no particular order, interspersed among open scopes. This is because
109 -- in the course of analyzing the context of a compilation, a package
110 -- declaration is first an open scope, and subsequently an element of the
111 -- context. If subunits or child units are present, a parent unit may
112 -- appear under various guises at various times in the compilation.
114 -- When the compilation of the innermost scope is complete, the entities
115 -- defined therein are no longer visible. If the scope is not a package
116 -- declaration, these entities are never visible subsequently, and can be
117 -- removed from visibility chains. If the scope is a package declaration,
118 -- its visible declarations may still be accessible. Therefore the entities
119 -- defined in such a scope are left on the visibility chains, and only
120 -- their visibility (immediately visibility or potential use-visibility)
123 -- The ordering of homonyms on their chain does not necessarily follow
124 -- the order of their corresponding scopes on the scope stack. For
125 -- example, if package P and the enclosing scope both contain entities
126 -- named E, then when compiling the package body the chain for E will
127 -- hold the global entity first, and the local one (corresponding to
128 -- the current inner scope) next. As a result, name resolution routines
129 -- do not assume any relative ordering of the homonym chains, either
130 -- for scope nesting or to order of appearance of context clauses.
132 -- When compiling a child unit, entities in the parent scope are always
133 -- immediately visible. When compiling the body of a child unit, private
134 -- entities in the parent must also be made immediately visible. There
135 -- are separate routines to make the visible and private declarations
136 -- visible at various times (see package Sem_Ch7).
138 -- +--------+ +-----+
139 -- | In use |-------->| EU1 |-------------------------->
140 -- +--------+ +-----+
142 -- +--------+ +-----+ +-----+
143 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
144 -- +--------+ +-----+ +-----+
146 -- +---------+ | +-----+
147 -- | with'ed |------------------------------>| EW2 |--->
148 -- +---------+ | +-----+
150 -- +--------+ +-----+ +-----+
151 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
152 -- +--------+ +-----+ +-----+
154 -- +--------+ +-----+ +-----+
155 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
156 -- +--------+ +-----+ +-----+
160 -- | | with'ed |----------------------------------------->
164 -- (innermost first) | |
165 -- +----------------------------+
166 -- Names table => | Id1 | | | | Id2 |
167 -- +----------------------------+
169 -- Name resolution must deal with several syntactic forms: simple names,
170 -- qualified names, indexed names, and various forms of calls.
172 -- Each identifier points to an entry in the names table. The resolution
173 -- of a simple name consists in traversing the homonym chain, starting
174 -- from the names table. If an entry is immediately visible, it is the one
175 -- designated by the identifier. If only potentially use-visible entities
176 -- are on the chain, we must verify that they do not hide each other. If
177 -- the entity we find is overloadable, we collect all other overloadable
178 -- entities on the chain as long as they are not hidden.
180 -- To resolve expanded names, we must find the entity at the intersection
181 -- of the entity chain for the scope (the prefix) and the homonym chain
182 -- for the selector. In general, homonym chains will be much shorter than
183 -- entity chains, so it is preferable to start from the names table as
184 -- well. If the entity found is overloadable, we must collect all other
185 -- interpretations that are defined in the scope denoted by the prefix.
187 -- For records, protected types, and tasks, their local entities are
188 -- removed from visibility chains on exit from the corresponding scope.
189 -- From the outside, these entities are always accessed by selected
190 -- notation, and the entity chain for the record type, protected type,
191 -- etc. is traversed sequentially in order to find the designated entity.
193 -- The discriminants of a type and the operations of a protected type or
194 -- task are unchained on exit from the first view of the type, (such as
195 -- a private or incomplete type declaration, or a protected type speci-
196 -- fication) and re-chained when compiling the second view.
198 -- In the case of operators, we do not make operators on derived types
199 -- explicit. As a result, the notation P."+" may denote either a user-
200 -- defined function with name "+", or else an implicit declaration of the
201 -- operator "+" in package P. The resolution of expanded names always
202 -- tries to resolve an operator name as such an implicitly defined entity,
203 -- in addition to looking for explicit declarations.
205 -- All forms of names that denote entities (simple names, expanded names,
206 -- character literals in some cases) have a Entity attribute, which
207 -- identifies the entity denoted by the name.
209 ---------------------
210 -- The Scope Stack --
211 ---------------------
213 -- The Scope stack keeps track of the scopes currently been compiled.
214 -- Every entity that contains declarations (including records) is placed
215 -- on the scope stack while it is being processed, and removed at the end.
216 -- Whenever a non-package scope is exited, the entities defined therein
217 -- are removed from the visibility table, so that entities in outer scopes
218 -- become visible (see previous description). On entry to Sem, the scope
219 -- stack only contains the package Standard. As usual, subunits complicate
220 -- this picture ever so slightly.
222 -- The Rtsfind mechanism can force a call to Semantics while another
223 -- compilation is in progress. The unit retrieved by Rtsfind must be
224 -- compiled in its own context, and has no access to the visibility of
225 -- the unit currently being compiled. The procedures Save_Scope_Stack and
226 -- Restore_Scope_Stack make entities in current open scopes invisible
227 -- before compiling the retrieved unit, and restore the compilation
228 -- environment afterwards.
230 ------------------------
231 -- Compiling subunits --
232 ------------------------
234 -- Subunits must be compiled in the environment of the corresponding stub,
235 -- that is to say with the same visibility into the parent (and its
236 -- context) that is available at the point of the stub declaration, but
237 -- with the additional visibility provided by the context clause of the
238 -- subunit itself. As a result, compilation of a subunit forces compilation
239 -- of the parent (see description in lib-). At the point of the stub
240 -- declaration, Analyze is called recursively to compile the proper body of
241 -- the subunit, but without reinitializing the names table, nor the scope
242 -- stack (i.e. standard is not pushed on the stack). In this fashion the
243 -- context of the subunit is added to the context of the parent, and the
244 -- subunit is compiled in the correct environment. Note that in the course
245 -- of processing the context of a subunit, Standard will appear twice on
246 -- the scope stack: once for the parent of the subunit, and once for the
247 -- unit in the context clause being compiled. However, the two sets of
248 -- entities are not linked by homonym chains, so that the compilation of
249 -- any context unit happens in a fresh visibility environment.
251 -------------------------------
252 -- Processing of USE Clauses --
253 -------------------------------
255 -- Every defining occurrence has a flag indicating if it is potentially use
256 -- visible. Resolution of simple names examines this flag. The processing
257 -- of use clauses consists in setting this flag on all visible entities
258 -- defined in the corresponding package. On exit from the scope of the use
259 -- clause, the corresponding flag must be reset. However, a package may
260 -- appear in several nested use clauses (pathological but legal, alas!)
261 -- which forces us to use a slightly more involved scheme:
263 -- a) The defining occurrence for a package holds a flag -In_Use- to
264 -- indicate that it is currently in the scope of a use clause. If a
265 -- redundant use clause is encountered, then the corresponding occurrence
266 -- of the package name is flagged -Redundant_Use-.
268 -- b) On exit from a scope, the use clauses in its declarative part are
269 -- scanned. The visibility flag is reset in all entities declared in
270 -- package named in a use clause, as long as the package is not flagged
271 -- as being in a redundant use clause (in which case the outer use
272 -- clause is still in effect, and the direct visibility of its entities
273 -- must be retained).
275 -- Note that entities are not removed from their homonym chains on exit
276 -- from the package specification. A subsequent use clause does not need
277 -- to rechain the visible entities, but only to establish their direct
280 -----------------------------------
281 -- Handling private declarations --
282 -----------------------------------
284 -- The principle that each entity has a single defining occurrence clashes
285 -- with the presence of two separate definitions for private types: the
286 -- first is the private type declaration, and second is the full type
287 -- declaration. It is important that all references to the type point to
288 -- the same defining occurrence, namely the first one. To enforce the two
289 -- separate views of the entity, the corresponding information is swapped
290 -- between the two declarations. Outside of the package, the defining
291 -- occurrence only contains the private declaration information, while in
292 -- the private part and the body of the package the defining occurrence
293 -- contains the full declaration. To simplify the swap, the defining
294 -- occurrence that currently holds the private declaration points to the
295 -- full declaration. During semantic processing the defining occurrence
296 -- also points to a list of private dependents, that is to say access types
297 -- or composite types whose designated types or component types are
298 -- subtypes or derived types of the private type in question. After the
299 -- full declaration has been seen, the private dependents are updated to
300 -- indicate that they have full definitions.
302 ------------------------------------
303 -- Handling of Undefined Messages --
304 ------------------------------------
306 -- In normal mode, only the first use of an undefined identifier generates
307 -- a message. The table Urefs is used to record error messages that have
308 -- been issued so that second and subsequent ones do not generate further
309 -- messages. However, the second reference causes text to be added to the
310 -- original undefined message noting "(more references follow)". The
311 -- full error list option (-gnatf) forces messages to be generated for
312 -- every reference and disconnects the use of this table.
314 type Uref_Entry is record
316 -- Node for identifier for which original message was posted. The
317 -- Chars field of this identifier is used to detect later references
318 -- to the same identifier.
321 -- Records error message Id of original undefined message. Reset to
322 -- No_Error_Msg after the second occurrence, where it is used to add
323 -- text to the original message as described above.
326 -- Set if the message is not visible rather than undefined
329 -- Records location of error message. Used to make sure that we do
330 -- not consider a, b : undefined as two separate instances, which
331 -- would otherwise happen, since the parser converts this sequence
332 -- to a : undefined; b : undefined.
336 package Urefs is new Table.Table (
337 Table_Component_Type => Uref_Entry,
338 Table_Index_Type => Nat,
339 Table_Low_Bound => 1,
341 Table_Increment => 100,
342 Table_Name => "Urefs");
344 Candidate_Renaming : Entity_Id;
345 -- Holds a candidate interpretation that appears in a subprogram renaming
346 -- declaration and does not match the given specification, but matches at
347 -- least on the first formal. Allows better error message when given
348 -- specification omits defaulted parameters, a common error.
350 -----------------------
351 -- Local Subprograms --
352 -----------------------
354 procedure Analyze_Generic_Renaming
357 -- Common processing for all three kinds of generic renaming declarations.
358 -- Enter new name and indicate that it renames the generic unit.
360 procedure Analyze_Renamed_Character
364 -- Renamed entity is given by a character literal, which must belong
365 -- to the return type of the new entity. Is_Body indicates whether the
366 -- declaration is a renaming_as_body. If the original declaration has
367 -- already been frozen (because of an intervening body, e.g.) the body of
368 -- the function must be built now. The same applies to the following
369 -- various renaming procedures.
371 procedure Analyze_Renamed_Dereference
375 -- Renamed entity is given by an explicit dereference. Prefix must be a
376 -- conformant access_to_subprogram type.
378 procedure Analyze_Renamed_Entry
382 -- If the renamed entity in a subprogram renaming is an entry or protected
383 -- subprogram, build a body for the new entity whose only statement is a
384 -- call to the renamed entity.
386 procedure Analyze_Renamed_Family_Member
390 -- Used when the renamed entity is an indexed component. The prefix must
391 -- denote an entry family.
393 procedure Analyze_Renamed_Primitive_Operation
397 -- If the renamed entity in a subprogram renaming is a primitive operation
398 -- or a class-wide operation in prefix form, save the target object, which
399 -- must be added to the list of actuals in any subsequent call.
401 function Applicable_Use (Pack_Name : Node_Id) return Boolean;
402 -- Common code to Use_One_Package and Set_Use, to determine whether use
403 -- clause must be processed. Pack_Name is an entity name that references
404 -- the package in question.
406 procedure Attribute_Renaming (N : Node_Id);
407 -- Analyze renaming of attribute as subprogram. The renaming declaration N
408 -- is rewritten as a subprogram body that returns the attribute reference
409 -- applied to the formals of the function.
411 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id);
412 -- Set Entity, with style check if need be. For a discriminant reference,
413 -- replace by the corresponding discriminal, i.e. the parameter of the
414 -- initialization procedure that corresponds to the discriminant.
416 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
417 -- A renaming_as_body may occur after the entity of the original decla-
418 -- ration has been frozen. In that case, the body of the new entity must
419 -- be built now, because the usual mechanism of building the renamed
420 -- body at the point of freezing will not work. Subp is the subprogram
421 -- for which N provides the Renaming_As_Body.
423 procedure Check_In_Previous_With_Clause
426 -- N is a use_package clause and Nam the package name, or N is a use_type
427 -- clause and Nam is the prefix of the type name. In either case, verify
428 -- that the package is visible at that point in the context: either it
429 -- appears in a previous with_clause, or because it is a fully qualified
430 -- name and the root ancestor appears in a previous with_clause.
432 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
433 -- Verify that the entity in a renaming declaration that is a library unit
434 -- is itself a library unit and not a nested unit or subunit. Also check
435 -- that if the renaming is a child unit of a generic parent, then the
436 -- renamed unit must also be a child unit of that parent. Finally, verify
437 -- that a renamed generic unit is not an implicit child declared within
438 -- an instance of the parent.
440 procedure Chain_Use_Clause (N : Node_Id);
441 -- Chain use clause onto list of uses clauses headed by First_Use_Clause in
442 -- the proper scope table entry. This is usually the current scope, but it
443 -- will be an inner scope when installing the use clauses of the private
444 -- declarations of a parent unit prior to compiling the private part of a
445 -- child unit. This chain is traversed when installing/removing use clauses
446 -- when compiling a subunit or instantiating a generic body on the fly,
447 -- when it is necessary to save and restore full environments.
449 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
450 -- Find a type derived from Character or Wide_Character in the prefix of N.
451 -- Used to resolved qualified names whose selector is a character literal.
453 function Has_Private_With (E : Entity_Id) return Boolean;
454 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
455 -- private with on E.
457 procedure Find_Expanded_Name (N : Node_Id);
458 -- The input is a selected component known to be an expanded name. Verify
459 -- legality of selector given the scope denoted by prefix, and change node
460 -- N into a expanded name with a properly set Entity field.
462 function Find_Renamed_Entity
466 Is_Actual : Boolean := False) return Entity_Id;
467 -- Find the renamed entity that corresponds to the given parameter profile
468 -- in a subprogram renaming declaration. The renamed entity may be an
469 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
470 -- indicates that the renaming is the one generated for an actual subpro-
471 -- gram in an instance, for which special visibility checks apply.
473 function Has_Implicit_Operator (N : Node_Id) return Boolean;
474 -- N is an expanded name whose selector is an operator name (e.g. P."+").
475 -- declarative part contains an implicit declaration of an operator if it
476 -- has a declaration of a type to which one of the predefined operators
477 -- apply. The existence of this routine is an implementation artifact. A
478 -- more straightforward but more space-consuming choice would be to make
479 -- all inherited operators explicit in the symbol table.
481 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
482 -- A subprogram defined by a renaming declaration inherits the parameter
483 -- profile of the renamed entity. The subtypes given in the subprogram
484 -- specification are discarded and replaced with those of the renamed
485 -- subprogram, which are then used to recheck the default values.
487 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
488 -- Prefix is appropriate for record if it is of a record type, or an access
491 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
492 -- True if it is of a task type, a protected type, or else an access to one
495 procedure Note_Redundant_Use (Clause : Node_Id);
496 -- Mark the name in a use clause as redundant if the corresponding entity
497 -- is already use-visible. Emit a warning if the use clause comes from
498 -- source and the proper warnings are enabled.
500 procedure Premature_Usage (N : Node_Id);
501 -- Diagnose usage of an entity before it is visible
503 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
504 -- Make visible entities declared in package P potentially use-visible
505 -- in the current context. Also used in the analysis of subunits, when
506 -- re-installing use clauses of parent units. N is the use_clause that
507 -- names P (and possibly other packages).
509 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False);
510 -- Id is the subtype mark from a use type clause. This procedure makes
511 -- the primitive operators of the type potentially use-visible. The
512 -- boolean flag Installed indicates that the clause is being reinstalled
513 -- after previous analysis, and primitive operations are already chained
514 -- on the Used_Operations list of the clause.
516 procedure Write_Info;
517 -- Write debugging information on entities declared in current scope
519 --------------------------------
520 -- Analyze_Exception_Renaming --
521 --------------------------------
523 -- The language only allows a single identifier, but the tree holds an
524 -- identifier list. The parser has already issued an error message if
525 -- there is more than one element in the list.
527 procedure Analyze_Exception_Renaming (N : Node_Id) is
528 Id : constant Node_Id := Defining_Identifier (N);
529 Nam : constant Node_Id := Name (N);
532 Check_SPARK_Restriction ("exception renaming is not allowed", N);
537 Set_Ekind (Id, E_Exception);
538 Set_Exception_Code (Id, Uint_0);
539 Set_Etype (Id, Standard_Exception_Type);
540 Set_Is_Pure (Id, Is_Pure (Current_Scope));
542 if not Is_Entity_Name (Nam) or else
543 Ekind (Entity (Nam)) /= E_Exception
545 Error_Msg_N ("invalid exception name in renaming", Nam);
547 if Present (Renamed_Object (Entity (Nam))) then
548 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
550 Set_Renamed_Object (Id, Entity (Nam));
553 end Analyze_Exception_Renaming;
555 ---------------------------
556 -- Analyze_Expanded_Name --
557 ---------------------------
559 procedure Analyze_Expanded_Name (N : Node_Id) is
561 -- If the entity pointer is already set, this is an internal node, or a
562 -- node that is analyzed more than once, after a tree modification. In
563 -- such a case there is no resolution to perform, just set the type. For
564 -- completeness, analyze prefix as well.
566 if Present (Entity (N)) then
567 if Is_Type (Entity (N)) then
568 Set_Etype (N, Entity (N));
570 Set_Etype (N, Etype (Entity (N)));
573 Analyze (Prefix (N));
576 Find_Expanded_Name (N);
578 end Analyze_Expanded_Name;
580 ---------------------------------------
581 -- Analyze_Generic_Function_Renaming --
582 ---------------------------------------
584 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
586 Analyze_Generic_Renaming (N, E_Generic_Function);
587 end Analyze_Generic_Function_Renaming;
589 --------------------------------------
590 -- Analyze_Generic_Package_Renaming --
591 --------------------------------------
593 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
595 -- Apply the Text_IO Kludge here, since we may be renaming one of the
596 -- subpackages of Text_IO, then join common routine.
598 Text_IO_Kludge (Name (N));
600 Analyze_Generic_Renaming (N, E_Generic_Package);
601 end Analyze_Generic_Package_Renaming;
603 ----------------------------------------
604 -- Analyze_Generic_Procedure_Renaming --
605 ----------------------------------------
607 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
609 Analyze_Generic_Renaming (N, E_Generic_Procedure);
610 end Analyze_Generic_Procedure_Renaming;
612 ------------------------------
613 -- Analyze_Generic_Renaming --
614 ------------------------------
616 procedure Analyze_Generic_Renaming
620 New_P : constant Entity_Id := Defining_Entity (N);
622 Inst : Boolean := False; -- prevent junk warning
625 if Name (N) = Error then
629 Check_SPARK_Restriction ("generic renaming is not allowed", N);
631 Generate_Definition (New_P);
633 if Current_Scope /= Standard_Standard then
634 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
637 if Nkind (Name (N)) = N_Selected_Component then
638 Check_Generic_Child_Unit (Name (N), Inst);
643 if not Is_Entity_Name (Name (N)) then
644 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
647 Old_P := Entity (Name (N));
651 Set_Ekind (New_P, K);
653 if Etype (Old_P) = Any_Type then
656 elsif Ekind (Old_P) /= K then
657 Error_Msg_N ("invalid generic unit name", Name (N));
660 if Present (Renamed_Object (Old_P)) then
661 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
663 Set_Renamed_Object (New_P, Old_P);
666 Set_Is_Pure (New_P, Is_Pure (Old_P));
667 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
669 Set_Etype (New_P, Etype (Old_P));
670 Set_Has_Completion (New_P);
672 if In_Open_Scopes (Old_P) then
673 Error_Msg_N ("within its scope, generic denotes its instance", N);
676 Check_Library_Unit_Renaming (N, Old_P);
678 end Analyze_Generic_Renaming;
680 -----------------------------
681 -- Analyze_Object_Renaming --
682 -----------------------------
684 procedure Analyze_Object_Renaming (N : Node_Id) is
685 Loc : constant Source_Ptr := Sloc (N);
686 Id : constant Entity_Id := Defining_Identifier (N);
688 Nam : constant Node_Id := Name (N);
692 procedure Check_Constrained_Object;
693 -- If the nominal type is unconstrained but the renamed object is
694 -- constrained, as can happen with renaming an explicit dereference or
695 -- a function return, build a constrained subtype from the object. If
696 -- the renaming is for a formal in an accept statement, the analysis
697 -- has already established its actual subtype. This is only relevant
698 -- if the renamed object is an explicit dereference.
700 function In_Generic_Scope (E : Entity_Id) return Boolean;
701 -- Determine whether entity E is inside a generic cope
703 ------------------------------
704 -- Check_Constrained_Object --
705 ------------------------------
707 procedure Check_Constrained_Object is
711 if Nkind_In (Nam, N_Function_Call, N_Explicit_Dereference)
712 and then Is_Composite_Type (Etype (Nam))
713 and then not Is_Constrained (Etype (Nam))
714 and then not Has_Unknown_Discriminants (Etype (Nam))
715 and then Expander_Active
717 -- If Actual_Subtype is already set, nothing to do
719 if Ekind_In (Id, E_Variable, E_Constant)
720 and then Present (Actual_Subtype (Id))
724 -- A renaming of an unchecked union does not have an
727 elsif Is_Unchecked_Union (Etype (Nam)) then
731 Subt := Make_Temporary (Loc, 'T');
732 Remove_Side_Effects (Nam);
734 Make_Subtype_Declaration (Loc,
735 Defining_Identifier => Subt,
736 Subtype_Indication =>
737 Make_Subtype_From_Expr (Nam, Etype (Nam))));
738 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
739 Set_Etype (Nam, Subt);
742 end Check_Constrained_Object;
744 ----------------------
745 -- In_Generic_Scope --
746 ----------------------
748 function In_Generic_Scope (E : Entity_Id) return Boolean is
753 while Present (S) and then S /= Standard_Standard loop
754 if Is_Generic_Unit (S) then
762 end In_Generic_Scope;
764 -- Start of processing for Analyze_Object_Renaming
771 Check_SPARK_Restriction ("object renaming is not allowed", N);
773 Set_Is_Pure (Id, Is_Pure (Current_Scope));
776 -- The renaming of a component that depends on a discriminant requires
777 -- an actual subtype, because in subsequent use of the object Gigi will
778 -- be unable to locate the actual bounds. This explicit step is required
779 -- when the renaming is generated in removing side effects of an
780 -- already-analyzed expression.
782 if Nkind (Nam) = N_Selected_Component
783 and then Analyzed (Nam)
786 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
788 if Present (Dec) then
789 Insert_Action (N, Dec);
790 T := Defining_Identifier (Dec);
794 -- Complete analysis of the subtype mark in any case, for ASIS use
796 if Present (Subtype_Mark (N)) then
797 Find_Type (Subtype_Mark (N));
800 elsif Present (Subtype_Mark (N)) then
801 Find_Type (Subtype_Mark (N));
802 T := Entity (Subtype_Mark (N));
805 -- Reject renamings of conversions unless the type is tagged, or
806 -- the conversion is implicit (which can occur for cases of anonymous
807 -- access types in Ada 2012).
809 if Nkind (Nam) = N_Type_Conversion
810 and then Comes_From_Source (Nam)
811 and then not Is_Tagged_Type (T)
814 ("renaming of conversion only allowed for tagged types", Nam);
819 -- If the renamed object is a function call of a limited type,
820 -- the expansion of the renaming is complicated by the presence
821 -- of various temporaries and subtypes that capture constraints
822 -- of the renamed object. Rewrite node as an object declaration,
823 -- whose expansion is simpler. Given that the object is limited
824 -- there is no copy involved and no performance hit.
826 if Nkind (Nam) = N_Function_Call
827 and then Is_Immutably_Limited_Type (Etype (Nam))
828 and then not Is_Constrained (Etype (Nam))
829 and then Comes_From_Source (N)
832 Set_Ekind (Id, E_Constant);
834 Make_Object_Declaration (Loc,
835 Defining_Identifier => Id,
836 Constant_Present => True,
837 Object_Definition => New_Occurrence_Of (Etype (Nam), Loc),
838 Expression => Relocate_Node (Nam)));
842 -- Ada 2012 (AI05-149): Reject renaming of an anonymous access object
843 -- when renaming declaration has a named access type. The Ada 2012
844 -- coverage rules allow an anonymous access type in the context of
845 -- an expected named general access type, but the renaming rules
846 -- require the types to be the same. (An exception is when the type
847 -- of the renaming is also an anonymous access type, which can only
848 -- happen due to a renaming created by the expander.)
850 if Nkind (Nam) = N_Type_Conversion
851 and then not Comes_From_Source (Nam)
852 and then Ekind (Etype (Expression (Nam))) = E_Anonymous_Access_Type
853 and then Ekind (T) /= E_Anonymous_Access_Type
855 Wrong_Type (Expression (Nam), T); -- Should we give better error???
858 -- Check that a class-wide object is not being renamed as an object
859 -- of a specific type. The test for access types is needed to exclude
860 -- cases where the renamed object is a dynamically tagged access
861 -- result, such as occurs in certain expansions.
863 if Is_Tagged_Type (T) then
864 Check_Dynamically_Tagged_Expression
870 -- Ada 2005 (AI-230/AI-254): Access renaming
872 else pragma Assert (Present (Access_Definition (N)));
873 T := Access_Definition
875 N => Access_Definition (N));
879 -- Ada 2005 AI05-105: if the declaration has an anonymous access
880 -- type, the renamed object must also have an anonymous type, and
881 -- this is a name resolution rule. This was implicit in the last part
882 -- of the first sentence in 8.5.1(3/2), and is made explicit by this
885 if not Is_Overloaded (Nam) then
886 if Ekind (Etype (Nam)) /= Ekind (T) then
888 ("expect anonymous access type in object renaming", N);
895 Typ : Entity_Id := Empty;
896 Seen : Boolean := False;
899 Get_First_Interp (Nam, I, It);
900 while Present (It.Typ) loop
902 -- Renaming is ambiguous if more than one candidate
903 -- interpretation is type-conformant with the context.
905 if Ekind (It.Typ) = Ekind (T) then
906 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
909 (Designated_Type (T), Designated_Type (It.Typ))
915 ("ambiguous expression in renaming", Nam);
918 elsif Ekind (T) = E_Anonymous_Access_Type
920 Covers (Designated_Type (T), Designated_Type (It.Typ))
926 ("ambiguous expression in renaming", Nam);
930 if Covers (T, It.Typ) then
932 Set_Etype (Nam, Typ);
933 Set_Is_Overloaded (Nam, False);
937 Get_Next_Interp (I, It);
944 -- Ada 2005 (AI-231): "In the case where the type is defined by an
945 -- access_definition, the renamed entity shall be of an access-to-
946 -- constant type if and only if the access_definition defines an
947 -- access-to-constant type" ARM 8.5.1(4)
949 if Constant_Present (Access_Definition (N))
950 and then not Is_Access_Constant (Etype (Nam))
952 Error_Msg_N ("(Ada 2005): the renamed object is not "
953 & "access-to-constant (RM 8.5.1(6))", N);
955 elsif not Constant_Present (Access_Definition (N))
956 and then Is_Access_Constant (Etype (Nam))
958 Error_Msg_N ("(Ada 2005): the renamed object is not "
959 & "access-to-variable (RM 8.5.1(6))", N);
962 if Is_Access_Subprogram_Type (Etype (Nam)) then
963 Check_Subtype_Conformant
964 (Designated_Type (T), Designated_Type (Etype (Nam)));
966 elsif not Subtypes_Statically_Match
967 (Designated_Type (T),
968 Available_View (Designated_Type (Etype (Nam))))
971 ("subtype of renamed object does not statically match", N);
975 -- Special processing for renaming function return object. Some errors
976 -- and warnings are produced only for calls that come from source.
978 if Nkind (Nam) = N_Function_Call then
981 -- Usage is illegal in Ada 83
984 if Comes_From_Source (Nam) then
986 ("(Ada 83) cannot rename function return object", Nam);
989 -- In Ada 95, warn for odd case of renaming parameterless function
990 -- call if this is not a limited type (where this is useful).
993 if Warn_On_Object_Renames_Function
994 and then No (Parameter_Associations (Nam))
995 and then not Is_Limited_Type (Etype (Nam))
996 and then Comes_From_Source (Nam)
999 ("?renaming function result object is suspicious", Nam);
1001 ("\?function & will be called only once", Nam,
1002 Entity (Name (Nam)));
1003 Error_Msg_N -- CODEFIX
1004 ("\?suggest using an initialized constant object instead",
1011 Check_Constrained_Object;
1013 -- An object renaming requires an exact match of the type. Class-wide
1014 -- matching is not allowed.
1016 if Is_Class_Wide_Type (T)
1017 and then Base_Type (Etype (Nam)) /= Base_Type (T)
1019 Wrong_Type (Nam, T);
1024 -- Ada 2005 (AI-326): Handle wrong use of incomplete type
1026 if Nkind (Nam) = N_Explicit_Dereference
1027 and then Ekind (Etype (T2)) = E_Incomplete_Type
1029 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
1032 elsif Ekind (Etype (T)) = E_Incomplete_Type then
1033 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
1037 -- Ada 2005 (AI-327)
1039 if Ada_Version >= Ada_2005
1040 and then Nkind (Nam) = N_Attribute_Reference
1041 and then Attribute_Name (Nam) = Name_Priority
1045 elsif Ada_Version >= Ada_2005
1046 and then Nkind (Nam) in N_Has_Entity
1050 Nam_Ent : Entity_Id;
1053 if Nkind (Nam) = N_Attribute_Reference then
1054 Nam_Ent := Entity (Prefix (Nam));
1056 Nam_Ent := Entity (Nam);
1059 Nam_Decl := Parent (Nam_Ent);
1061 if Has_Null_Exclusion (N)
1062 and then not Has_Null_Exclusion (Nam_Decl)
1064 -- Ada 2005 (AI-423): If the object name denotes a generic
1065 -- formal object of a generic unit G, and the object renaming
1066 -- declaration occurs within the body of G or within the body
1067 -- of a generic unit declared within the declarative region
1068 -- of G, then the declaration of the formal object of G must
1069 -- have a null exclusion or a null-excluding subtype.
1071 if Is_Formal_Object (Nam_Ent)
1072 and then In_Generic_Scope (Id)
1074 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
1076 ("renamed formal does not exclude `NULL` "
1077 & "(RM 8.5.1(4.6/2))", N);
1079 elsif In_Package_Body (Scope (Id)) then
1081 ("formal object does not have a null exclusion"
1082 & "(RM 8.5.1(4.6/2))", N);
1085 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1086 -- shall exclude null.
1088 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1090 ("renamed object does not exclude `NULL` "
1091 & "(RM 8.5.1(4.6/2))", N);
1093 -- An instance is illegal if it contains a renaming that
1094 -- excludes null, and the actual does not. The renaming
1095 -- declaration has already indicated that the declaration
1096 -- of the renamed actual in the instance will raise
1097 -- constraint_error.
1099 elsif Nkind (Nam_Decl) = N_Object_Declaration
1100 and then In_Instance
1102 (Corresponding_Generic_Association (Nam_Decl))
1103 and then Nkind (Expression (Nam_Decl))
1104 = N_Raise_Constraint_Error
1107 ("renamed actual does not exclude `NULL` "
1108 & "(RM 8.5.1(4.6/2))", N);
1110 -- Finally, if there is a null exclusion, the subtype mark
1111 -- must not be null-excluding.
1113 elsif No (Access_Definition (N))
1114 and then Can_Never_Be_Null (T)
1117 ("`NOT NULL` not allowed (& already excludes null)",
1122 elsif Can_Never_Be_Null (T)
1123 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1126 ("renamed object does not exclude `NULL` "
1127 & "(RM 8.5.1(4.6/2))", N);
1129 elsif Has_Null_Exclusion (N)
1130 and then No (Access_Definition (N))
1131 and then Can_Never_Be_Null (T)
1134 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1139 Set_Ekind (Id, E_Variable);
1141 -- Initialize the object size and alignment. Note that we used to call
1142 -- Init_Size_Align here, but that's wrong for objects which have only
1143 -- an Esize, not an RM_Size field!
1145 Init_Object_Size_Align (Id);
1147 if T = Any_Type or else Etype (Nam) = Any_Type then
1150 -- Verify that the renamed entity is an object or a function call. It
1151 -- may have been rewritten in several ways.
1153 elsif Is_Object_Reference (Nam) then
1154 if Comes_From_Source (N)
1155 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
1158 ("illegal renaming of discriminant-dependent component", Nam);
1161 -- A static function call may have been folded into a literal
1163 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1165 -- When expansion is disabled, attribute reference is not
1166 -- rewritten as function call. Otherwise it may be rewritten
1167 -- as a conversion, so check original node.
1169 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1170 and then Is_Function_Attribute_Name
1171 (Attribute_Name (Original_Node (Nam))))
1173 -- Weird but legal, equivalent to renaming a function call.
1174 -- Illegal if the literal is the result of constant-folding an
1175 -- attribute reference that is not a function.
1177 or else (Is_Entity_Name (Nam)
1178 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1180 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1182 or else (Nkind (Nam) = N_Type_Conversion
1183 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1187 elsif Nkind (Nam) = N_Type_Conversion then
1189 ("renaming of conversion only allowed for tagged types", Nam);
1191 -- Ada 2005 (AI-327)
1193 elsif Ada_Version >= Ada_2005
1194 and then Nkind (Nam) = N_Attribute_Reference
1195 and then Attribute_Name (Nam) = Name_Priority
1199 -- Allow internally generated x'Reference expression
1201 elsif Nkind (Nam) = N_Reference then
1205 Error_Msg_N ("expect object name in renaming", Nam);
1210 if not Is_Variable (Nam) then
1211 Set_Ekind (Id, E_Constant);
1212 Set_Never_Set_In_Source (Id, True);
1213 Set_Is_True_Constant (Id, True);
1216 Set_Renamed_Object (Id, Nam);
1217 end Analyze_Object_Renaming;
1219 ------------------------------
1220 -- Analyze_Package_Renaming --
1221 ------------------------------
1223 procedure Analyze_Package_Renaming (N : Node_Id) is
1224 New_P : constant Entity_Id := Defining_Entity (N);
1229 if Name (N) = Error then
1233 -- Apply Text_IO kludge here since we may be renaming a child of Text_IO
1235 Text_IO_Kludge (Name (N));
1237 if Current_Scope /= Standard_Standard then
1238 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1244 if Is_Entity_Name (Name (N)) then
1245 Old_P := Entity (Name (N));
1250 if Etype (Old_P) = Any_Type then
1251 Error_Msg_N ("expect package name in renaming", Name (N));
1253 elsif Ekind (Old_P) /= E_Package
1254 and then not (Ekind (Old_P) = E_Generic_Package
1255 and then In_Open_Scopes (Old_P))
1257 if Ekind (Old_P) = E_Generic_Package then
1259 ("generic package cannot be renamed as a package", Name (N));
1261 Error_Msg_Sloc := Sloc (Old_P);
1263 ("expect package name in renaming, found& declared#",
1267 -- Set basic attributes to minimize cascaded errors
1269 Set_Ekind (New_P, E_Package);
1270 Set_Etype (New_P, Standard_Void_Type);
1272 -- Here for OK package renaming
1275 -- Entities in the old package are accessible through the renaming
1276 -- entity. The simplest implementation is to have both packages share
1279 Set_Ekind (New_P, E_Package);
1280 Set_Etype (New_P, Standard_Void_Type);
1282 if Present (Renamed_Object (Old_P)) then
1283 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1285 Set_Renamed_Object (New_P, Old_P);
1288 Set_Has_Completion (New_P);
1290 Set_First_Entity (New_P, First_Entity (Old_P));
1291 Set_Last_Entity (New_P, Last_Entity (Old_P));
1292 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1293 Check_Library_Unit_Renaming (N, Old_P);
1294 Generate_Reference (Old_P, Name (N));
1296 -- If the renaming is in the visible part of a package, then we set
1297 -- Renamed_In_Spec for the renamed package, to prevent giving
1298 -- warnings about no entities referenced. Such a warning would be
1299 -- overenthusiastic, since clients can see entities in the renamed
1300 -- package via the visible package renaming.
1303 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1305 if Ekind (Ent) = E_Package
1306 and then not In_Private_Part (Ent)
1307 and then In_Extended_Main_Source_Unit (N)
1308 and then Ekind (Old_P) = E_Package
1310 Set_Renamed_In_Spec (Old_P);
1314 -- If this is the renaming declaration of a package instantiation
1315 -- within itself, it is the declaration that ends the list of actuals
1316 -- for the instantiation. At this point, the subtypes that rename
1317 -- the actuals are flagged as generic, to avoid spurious ambiguities
1318 -- if the actuals for two distinct formals happen to coincide. If
1319 -- the actual is a private type, the subtype has a private completion
1320 -- that is flagged in the same fashion.
1322 -- Resolution is identical to what is was in the original generic.
1323 -- On exit from the generic instance, these are turned into regular
1324 -- subtypes again, so they are compatible with types in their class.
1326 if not Is_Generic_Instance (Old_P) then
1329 Spec := Specification (Unit_Declaration_Node (Old_P));
1332 if Nkind (Spec) = N_Package_Specification
1333 and then Present (Generic_Parent (Spec))
1334 and then Old_P = Current_Scope
1335 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1341 E := First_Entity (Old_P);
1346 and then Nkind (Parent (E)) = N_Subtype_Declaration
1348 Set_Is_Generic_Actual_Type (E);
1350 if Is_Private_Type (E)
1351 and then Present (Full_View (E))
1353 Set_Is_Generic_Actual_Type (Full_View (E));
1362 end Analyze_Package_Renaming;
1364 -------------------------------
1365 -- Analyze_Renamed_Character --
1366 -------------------------------
1368 procedure Analyze_Renamed_Character
1373 C : constant Node_Id := Name (N);
1376 if Ekind (New_S) = E_Function then
1377 Resolve (C, Etype (New_S));
1380 Check_Frozen_Renaming (N, New_S);
1384 Error_Msg_N ("character literal can only be renamed as function", N);
1386 end Analyze_Renamed_Character;
1388 ---------------------------------
1389 -- Analyze_Renamed_Dereference --
1390 ---------------------------------
1392 procedure Analyze_Renamed_Dereference
1397 Nam : constant Node_Id := Name (N);
1398 P : constant Node_Id := Prefix (Nam);
1404 if not Is_Overloaded (P) then
1405 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1406 or else not Type_Conformant (Etype (Nam), New_S)
1408 Error_Msg_N ("designated type does not match specification", P);
1417 Get_First_Interp (Nam, Ind, It);
1419 while Present (It.Nam) loop
1421 if Ekind (It.Nam) = E_Subprogram_Type
1422 and then Type_Conformant (It.Nam, New_S)
1424 if Typ /= Any_Id then
1425 Error_Msg_N ("ambiguous renaming", P);
1432 Get_Next_Interp (Ind, It);
1435 if Typ = Any_Type then
1436 Error_Msg_N ("designated type does not match specification", P);
1441 Check_Frozen_Renaming (N, New_S);
1445 end Analyze_Renamed_Dereference;
1447 ---------------------------
1448 -- Analyze_Renamed_Entry --
1449 ---------------------------
1451 procedure Analyze_Renamed_Entry
1456 Nam : constant Node_Id := Name (N);
1457 Sel : constant Node_Id := Selector_Name (Nam);
1461 if Entity (Sel) = Any_Id then
1463 -- Selector is undefined on prefix. Error emitted already
1465 Set_Has_Completion (New_S);
1469 -- Otherwise find renamed entity and build body of New_S as a call to it
1471 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1473 if Old_S = Any_Id then
1474 Error_Msg_N (" no subprogram or entry matches specification", N);
1477 Check_Subtype_Conformant (New_S, Old_S, N);
1478 Generate_Reference (New_S, Defining_Entity (N), 'b');
1479 Style.Check_Identifier (Defining_Entity (N), New_S);
1482 -- Only mode conformance required for a renaming_as_declaration
1484 Check_Mode_Conformant (New_S, Old_S, N);
1487 Inherit_Renamed_Profile (New_S, Old_S);
1489 -- The prefix can be an arbitrary expression that yields a task type,
1490 -- so it must be resolved.
1492 Resolve (Prefix (Nam), Scope (Old_S));
1495 Set_Convention (New_S, Convention (Old_S));
1496 Set_Has_Completion (New_S, Inside_A_Generic);
1499 Check_Frozen_Renaming (N, New_S);
1501 end Analyze_Renamed_Entry;
1503 -----------------------------------
1504 -- Analyze_Renamed_Family_Member --
1505 -----------------------------------
1507 procedure Analyze_Renamed_Family_Member
1512 Nam : constant Node_Id := Name (N);
1513 P : constant Node_Id := Prefix (Nam);
1517 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1518 or else (Nkind (P) = N_Selected_Component
1520 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1522 if Is_Entity_Name (P) then
1523 Old_S := Entity (P);
1525 Old_S := Entity (Selector_Name (P));
1528 if not Entity_Matches_Spec (Old_S, New_S) then
1529 Error_Msg_N ("entry family does not match specification", N);
1532 Check_Subtype_Conformant (New_S, Old_S, N);
1533 Generate_Reference (New_S, Defining_Entity (N), 'b');
1534 Style.Check_Identifier (Defining_Entity (N), New_S);
1538 Error_Msg_N ("no entry family matches specification", N);
1541 Set_Has_Completion (New_S, Inside_A_Generic);
1544 Check_Frozen_Renaming (N, New_S);
1546 end Analyze_Renamed_Family_Member;
1548 -----------------------------------------
1549 -- Analyze_Renamed_Primitive_Operation --
1550 -----------------------------------------
1552 procedure Analyze_Renamed_Primitive_Operation
1561 Ctyp : Conformance_Type) return Boolean;
1562 -- Verify that the signatures of the renamed entity and the new entity
1563 -- match. The first formal of the renamed entity is skipped because it
1564 -- is the target object in any subsequent call.
1568 Ctyp : Conformance_Type) return Boolean
1574 if Ekind (Subp) /= Ekind (New_S) then
1578 Old_F := Next_Formal (First_Formal (Subp));
1579 New_F := First_Formal (New_S);
1580 while Present (Old_F) and then Present (New_F) loop
1581 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1585 if Ctyp >= Mode_Conformant
1586 and then Ekind (Old_F) /= Ekind (New_F)
1591 Next_Formal (New_F);
1592 Next_Formal (Old_F);
1599 if not Is_Overloaded (Selector_Name (Name (N))) then
1600 Old_S := Entity (Selector_Name (Name (N)));
1602 if not Conforms (Old_S, Type_Conformant) then
1607 -- Find the operation that matches the given signature
1615 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1617 while Present (It.Nam) loop
1618 if Conforms (It.Nam, Type_Conformant) then
1622 Get_Next_Interp (Ind, It);
1627 if Old_S = Any_Id then
1628 Error_Msg_N (" no subprogram or entry matches specification", N);
1632 if not Conforms (Old_S, Subtype_Conformant) then
1633 Error_Msg_N ("subtype conformance error in renaming", N);
1636 Generate_Reference (New_S, Defining_Entity (N), 'b');
1637 Style.Check_Identifier (Defining_Entity (N), New_S);
1640 -- Only mode conformance required for a renaming_as_declaration
1642 if not Conforms (Old_S, Mode_Conformant) then
1643 Error_Msg_N ("mode conformance error in renaming", N);
1647 -- Inherit_Renamed_Profile (New_S, Old_S);
1649 -- The prefix can be an arbitrary expression that yields an
1650 -- object, so it must be resolved.
1652 Resolve (Prefix (Name (N)));
1654 end Analyze_Renamed_Primitive_Operation;
1656 ---------------------------------
1657 -- Analyze_Subprogram_Renaming --
1658 ---------------------------------
1660 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1661 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1662 Is_Actual : constant Boolean := Present (Formal_Spec);
1663 Inst_Node : Node_Id := Empty;
1664 Nam : constant Node_Id := Name (N);
1666 Old_S : Entity_Id := Empty;
1667 Rename_Spec : Entity_Id;
1668 Save_AV : constant Ada_Version_Type := Ada_Version;
1669 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1670 Spec : constant Node_Id := Specification (N);
1672 procedure Check_Null_Exclusion
1675 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1676 -- following AI rules:
1678 -- If Ren is a renaming of a formal subprogram and one of its
1679 -- parameters has a null exclusion, then the corresponding formal
1680 -- in Sub must also have one. Otherwise the subtype of the Sub's
1681 -- formal parameter must exclude null.
1683 -- If Ren is a renaming of a formal function and its return
1684 -- profile has a null exclusion, then Sub's return profile must
1685 -- have one. Otherwise the subtype of Sub's return profile must
1688 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1689 -- Find renamed entity when the declaration is a renaming_as_body and
1690 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1691 -- rule that a renaming_as_body is illegal if the declaration occurs
1692 -- before the subprogram it completes is frozen, and renaming indirectly
1693 -- renames the subprogram itself.(Defect Report 8652/0027).
1695 function Check_Class_Wide_Actual return Entity_Id;
1696 -- AI05-0071: In an instance, if the actual for a formal type FT with
1697 -- unknown discriminants is a class-wide type CT, and the generic has
1698 -- a formal subprogram with a box for a primitive operation of FT,
1699 -- then the corresponding actual subprogram denoted by the default is a
1700 -- class-wide operation whose body is a dispatching call. We replace the
1701 -- generated renaming declaration:
1703 -- procedure P (X : CT) renames P;
1705 -- by a different renaming and a class-wide operation:
1707 -- procedure Pr (X : T) renames P; -- renames primitive operation
1708 -- procedure P (X : CT); -- class-wide operation
1710 -- procedure P (X : CT) is begin Pr (X); end; -- dispatching call
1712 -- This rule only applies if there is no explicit visible class-wide
1713 -- operation at the point of the instantiation.
1715 function Has_Class_Wide_Actual return Boolean;
1716 -- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a
1717 -- defaulted formal subprogram when the actual for the controlling
1718 -- formal type is class-wide.
1720 -----------------------------
1721 -- Check_Class_Wide_Actual --
1722 -----------------------------
1724 function Check_Class_Wide_Actual return Entity_Id is
1725 Loc : constant Source_Ptr := Sloc (N);
1728 Formal_Type : Entity_Id;
1729 Actual_Type : Entity_Id;
1734 function Make_Call (Prim_Op : Entity_Id) return Node_Id;
1735 -- Build dispatching call for body of class-wide operation
1737 function Make_Spec return Node_Id;
1738 -- Create subprogram specification for declaration and body of
1739 -- class-wide operation, using signature of renaming declaration.
1745 function Make_Call (Prim_Op : Entity_Id) return Node_Id is
1750 Actuals := New_List;
1751 F := First (Parameter_Specifications (Specification (New_Decl)));
1752 while Present (F) loop
1754 Make_Identifier (Loc, Chars (Defining_Identifier (F))));
1758 if Ekind_In (Prim_Op, E_Function, E_Operator) then
1759 return Make_Simple_Return_Statement (Loc,
1761 Make_Function_Call (Loc,
1762 Name => New_Occurrence_Of (Prim_Op, Loc),
1763 Parameter_Associations => Actuals));
1766 Make_Procedure_Call_Statement (Loc,
1767 Name => New_Occurrence_Of (Prim_Op, Loc),
1768 Parameter_Associations => Actuals);
1776 function Make_Spec return Node_Id is
1777 Param_Specs : constant List_Id := Copy_Parameter_List (New_S);
1780 if Ekind (New_S) = E_Procedure then
1782 Make_Procedure_Specification (Loc,
1783 Defining_Unit_Name =>
1784 Make_Defining_Identifier (Loc,
1785 Chars (Defining_Unit_Name (Spec))),
1786 Parameter_Specifications => Param_Specs);
1789 Make_Function_Specification (Loc,
1790 Defining_Unit_Name =>
1791 Make_Defining_Identifier (Loc,
1792 Chars (Defining_Unit_Name (Spec))),
1793 Parameter_Specifications => Param_Specs,
1794 Result_Definition =>
1795 New_Copy_Tree (Result_Definition (Spec)));
1799 -- Start of processing for Check_Class_Wide_Actual
1803 Formal_Type := Empty;
1804 Actual_Type := Empty;
1806 F := First_Formal (Formal_Spec);
1807 while Present (F) loop
1808 if Has_Unknown_Discriminants (Etype (F))
1809 and then not Is_Class_Wide_Type (Etype (F))
1810 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F)))
1812 Formal_Type := Etype (F);
1813 Actual_Type := Etype (Get_Instance_Of (Formal_Type));
1820 if Present (Formal_Type) then
1822 -- Create declaration and body for class-wide operation
1825 Make_Subprogram_Declaration (Loc, Specification => Make_Spec);
1828 Make_Subprogram_Body (Loc,
1829 Specification => Make_Spec,
1830 Declarations => No_List,
1831 Handled_Statement_Sequence =>
1832 Make_Handled_Sequence_Of_Statements (Loc, New_List));
1834 -- Modify Spec and create internal name for renaming of primitive
1837 Set_Defining_Unit_Name (Spec, Make_Temporary (Loc, 'R'));
1838 F := First (Parameter_Specifications (Spec));
1839 while Present (F) loop
1840 if Nkind (Parameter_Type (F)) = N_Identifier
1841 and then Is_Class_Wide_Type (Entity (Parameter_Type (F)))
1843 Set_Parameter_Type (F, New_Occurrence_Of (Actual_Type, Loc));
1848 New_S := Analyze_Subprogram_Specification (Spec);
1849 Result := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1852 if Result /= Any_Id then
1853 Insert_Before (N, New_Decl);
1856 -- Add dispatching call to body of class-wide operation
1858 Append (Make_Call (Result),
1859 Statements (Handled_Statement_Sequence (New_Body)));
1861 -- The generated body does not freeze. It is analyzed when the
1862 -- generated operation is frozen. This body is only needed if
1863 -- expansion is enabled.
1865 if Expander_Active then
1866 Append_Freeze_Action (Defining_Entity (New_Decl), New_Body);
1869 Result := Defining_Entity (New_Decl);
1872 -- Return the class-wide operation if one was created
1875 end Check_Class_Wide_Actual;
1877 --------------------------
1878 -- Check_Null_Exclusion --
1879 --------------------------
1881 procedure Check_Null_Exclusion
1885 Ren_Formal : Entity_Id;
1886 Sub_Formal : Entity_Id;
1891 Ren_Formal := First_Formal (Ren);
1892 Sub_Formal := First_Formal (Sub);
1893 while Present (Ren_Formal)
1894 and then Present (Sub_Formal)
1896 if Has_Null_Exclusion (Parent (Ren_Formal))
1898 not (Has_Null_Exclusion (Parent (Sub_Formal))
1899 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1902 ("`NOT NULL` required for parameter &",
1903 Parent (Sub_Formal), Sub_Formal);
1906 Next_Formal (Ren_Formal);
1907 Next_Formal (Sub_Formal);
1910 -- Return profile check
1912 if Nkind (Parent (Ren)) = N_Function_Specification
1913 and then Nkind (Parent (Sub)) = N_Function_Specification
1914 and then Has_Null_Exclusion (Parent (Ren))
1916 not (Has_Null_Exclusion (Parent (Sub))
1917 or else Can_Never_Be_Null (Etype (Sub)))
1920 ("return must specify `NOT NULL`",
1921 Result_Definition (Parent (Sub)));
1923 end Check_Null_Exclusion;
1925 ---------------------------
1926 -- Has_Class_Wide_Actual --
1927 ---------------------------
1929 function Has_Class_Wide_Actual return Boolean is
1935 and then Nkind (Nam) in N_Has_Entity
1936 and then Present (Entity (Nam))
1937 and then Is_Dispatching_Operation (Entity (Nam))
1939 F_Nam := First_Entity (Entity (Nam));
1940 F_Spec := First_Formal (Formal_Spec);
1941 while Present (F_Nam)
1942 and then Present (F_Spec)
1944 if Is_Controlling_Formal (F_Nam)
1945 and then Has_Unknown_Discriminants (Etype (F_Spec))
1946 and then not Is_Class_Wide_Type (Etype (F_Spec))
1947 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F_Spec)))
1952 Next_Entity (F_Nam);
1953 Next_Formal (F_Spec);
1958 end Has_Class_Wide_Actual;
1960 -------------------------
1961 -- Original_Subprogram --
1962 -------------------------
1964 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1965 Orig_Decl : Node_Id;
1966 Orig_Subp : Entity_Id;
1969 -- First case: renamed entity is itself a renaming
1971 if Present (Alias (Subp)) then
1972 return Alias (Subp);
1975 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1977 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1979 -- Check if renamed entity is a renaming_as_body
1982 Unit_Declaration_Node
1983 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1985 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1986 Orig_Subp := Entity (Name (Orig_Decl));
1988 if Orig_Subp = Rename_Spec then
1990 -- Circularity detected
1995 return (Original_Subprogram (Orig_Subp));
2003 end Original_Subprogram;
2005 CW_Actual : constant Boolean := Has_Class_Wide_Actual;
2006 -- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a
2007 -- defaulted formal subprogram when the actual for a related formal
2008 -- type is class-wide.
2010 -- Start of processing for Analyze_Subprogram_Renaming
2013 -- We must test for the attribute renaming case before the Analyze
2014 -- call because otherwise Sem_Attr will complain that the attribute
2015 -- is missing an argument when it is analyzed.
2017 if Nkind (Nam) = N_Attribute_Reference then
2019 -- In the case of an abstract formal subprogram association, rewrite
2020 -- an actual given by a stream attribute as the name of the
2021 -- corresponding stream primitive of the type.
2023 -- In a generic context the stream operations are not generated, and
2024 -- this must be treated as a normal attribute reference, to be
2025 -- expanded in subsequent instantiations.
2027 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
2028 and then Full_Expander_Active
2031 Stream_Prim : Entity_Id;
2032 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
2035 -- The class-wide forms of the stream attributes are not
2036 -- primitive dispatching operations (even though they
2037 -- internally dispatch to a stream attribute).
2039 if Is_Class_Wide_Type (Prefix_Type) then
2041 ("attribute must be a primitive dispatching operation",
2046 -- Retrieve the primitive subprogram associated with the
2047 -- attribute. This can only be a stream attribute, since those
2048 -- are the only ones that are dispatching (and the actual for
2049 -- an abstract formal subprogram must be dispatching
2053 case Attribute_Name (Nam) is
2056 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
2059 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
2062 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
2065 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
2068 ("attribute must be a primitive"
2069 & " dispatching operation", Nam);
2075 -- If no operation was found, and the type is limited,
2076 -- the user should have defined one.
2078 when Program_Error =>
2079 if Is_Limited_Type (Prefix_Type) then
2081 ("stream operation not defined for type&",
2085 -- Otherwise, compiler should have generated default
2092 -- Rewrite the attribute into the name of its corresponding
2093 -- primitive dispatching subprogram. We can then proceed with
2094 -- the usual processing for subprogram renamings.
2097 Prim_Name : constant Node_Id :=
2098 Make_Identifier (Sloc (Nam),
2099 Chars => Chars (Stream_Prim));
2101 Set_Entity (Prim_Name, Stream_Prim);
2102 Rewrite (Nam, Prim_Name);
2107 -- Normal processing for a renaming of an attribute
2110 Attribute_Renaming (N);
2115 -- Check whether this declaration corresponds to the instantiation
2116 -- of a formal subprogram.
2118 -- If this is an instantiation, the corresponding actual is frozen and
2119 -- error messages can be made more precise. If this is a default
2120 -- subprogram, the entity is already established in the generic, and is
2121 -- not retrieved by visibility. If it is a default with a box, the
2122 -- candidate interpretations, if any, have been collected when building
2123 -- the renaming declaration. If overloaded, the proper interpretation is
2124 -- determined in Find_Renamed_Entity. If the entity is an operator,
2125 -- Find_Renamed_Entity applies additional visibility checks.
2128 Inst_Node := Unit_Declaration_Node (Formal_Spec);
2130 -- Check whether the renaming is for a defaulted actual subprogram
2131 -- with a class-wide actual.
2134 New_S := Analyze_Subprogram_Specification (Spec);
2135 Old_S := Check_Class_Wide_Actual;
2137 elsif Is_Entity_Name (Nam)
2138 and then Present (Entity (Nam))
2139 and then not Comes_From_Source (Nam)
2140 and then not Is_Overloaded (Nam)
2142 Old_S := Entity (Nam);
2143 New_S := Analyze_Subprogram_Specification (Spec);
2147 if Ekind (Entity (Nam)) = E_Operator then
2151 if Box_Present (Inst_Node) then
2152 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2154 -- If there is an immediately visible homonym of the operator
2155 -- and the declaration has a default, this is worth a warning
2156 -- because the user probably did not intend to get the pre-
2157 -- defined operator, visible in the generic declaration. To
2158 -- find if there is an intended candidate, analyze the renaming
2159 -- again in the current context.
2161 elsif Scope (Old_S) = Standard_Standard
2162 and then Present (Default_Name (Inst_Node))
2165 Decl : constant Node_Id := New_Copy_Tree (N);
2169 Set_Entity (Name (Decl), Empty);
2170 Analyze (Name (Decl));
2172 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
2175 and then In_Open_Scopes (Scope (Hidden))
2176 and then Is_Immediately_Visible (Hidden)
2177 and then Comes_From_Source (Hidden)
2178 and then Hidden /= Old_S
2180 Error_Msg_Sloc := Sloc (Hidden);
2181 Error_Msg_N ("?default subprogram is resolved " &
2182 "in the generic declaration " &
2183 "(RM 12.6(17))", N);
2184 Error_Msg_NE ("\?and will not use & #", N, Hidden);
2192 New_S := Analyze_Subprogram_Specification (Spec);
2196 -- Renamed entity must be analyzed first, to avoid being hidden by
2197 -- new name (which might be the same in a generic instance).
2201 -- The renaming defines a new overloaded entity, which is analyzed
2202 -- like a subprogram declaration.
2204 New_S := Analyze_Subprogram_Specification (Spec);
2207 if Current_Scope /= Standard_Standard then
2208 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
2211 Rename_Spec := Find_Corresponding_Spec (N);
2213 -- Case of Renaming_As_Body
2215 if Present (Rename_Spec) then
2217 -- Renaming declaration is the completion of the declaration of
2218 -- Rename_Spec. We build an actual body for it at the freezing point.
2220 Set_Corresponding_Spec (N, Rename_Spec);
2222 -- Deal with special case of stream functions of abstract types
2225 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
2226 N_Abstract_Subprogram_Declaration
2228 -- Input stream functions are abstract if the object type is
2229 -- abstract. Similarly, all default stream functions for an
2230 -- interface type are abstract. However, these subprograms may
2231 -- receive explicit declarations in representation clauses, making
2232 -- the attribute subprograms usable as defaults in subsequent
2234 -- In this case we rewrite the declaration to make the subprogram
2235 -- non-abstract. We remove the previous declaration, and insert
2236 -- the new one at the point of the renaming, to prevent premature
2237 -- access to unfrozen types. The new declaration reuses the
2238 -- specification of the previous one, and must not be analyzed.
2241 (Is_Primitive (Entity (Nam))
2243 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
2245 Old_Decl : constant Node_Id :=
2246 Unit_Declaration_Node (Rename_Spec);
2247 New_Decl : constant Node_Id :=
2248 Make_Subprogram_Declaration (Sloc (N),
2250 Relocate_Node (Specification (Old_Decl)));
2253 Insert_After (N, New_Decl);
2254 Set_Is_Abstract_Subprogram (Rename_Spec, False);
2255 Set_Analyzed (New_Decl);
2259 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
2261 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
2262 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
2265 Set_Convention (New_S, Convention (Rename_Spec));
2266 Check_Fully_Conformant (New_S, Rename_Spec);
2267 Set_Public_Status (New_S);
2269 -- The specification does not introduce new formals, but only
2270 -- repeats the formals of the original subprogram declaration.
2271 -- For cross-reference purposes, and for refactoring tools, we
2272 -- treat the formals of the renaming declaration as body formals.
2274 Reference_Body_Formals (Rename_Spec, New_S);
2276 -- Indicate that the entity in the declaration functions like the
2277 -- corresponding body, and is not a new entity. The body will be
2278 -- constructed later at the freeze point, so indicate that the
2279 -- completion has not been seen yet.
2281 Set_Ekind (New_S, E_Subprogram_Body);
2282 New_S := Rename_Spec;
2283 Set_Has_Completion (Rename_Spec, False);
2285 -- Ada 2005: check overriding indicator
2287 if Present (Overridden_Operation (Rename_Spec)) then
2288 if Must_Not_Override (Specification (N)) then
2290 ("subprogram& overrides inherited operation",
2293 Style_Check and then not Must_Override (Specification (N))
2295 Style.Missing_Overriding (N, Rename_Spec);
2298 elsif Must_Override (Specification (N)) then
2299 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
2302 -- Normal subprogram renaming (not renaming as body)
2305 Generate_Definition (New_S);
2306 New_Overloaded_Entity (New_S);
2308 if Is_Entity_Name (Nam)
2309 and then Is_Intrinsic_Subprogram (Entity (Nam))
2313 Check_Delayed_Subprogram (New_S);
2317 -- There is no need for elaboration checks on the new entity, which may
2318 -- be called before the next freezing point where the body will appear.
2319 -- Elaboration checks refer to the real entity, not the one created by
2320 -- the renaming declaration.
2322 Set_Kill_Elaboration_Checks (New_S, True);
2324 if Etype (Nam) = Any_Type then
2325 Set_Has_Completion (New_S);
2328 elsif Nkind (Nam) = N_Selected_Component then
2330 -- A prefix of the form A.B can designate an entry of task A, a
2331 -- protected operation of protected object A, or finally a primitive
2332 -- operation of object A. In the later case, A is an object of some
2333 -- tagged type, or an access type that denotes one such. To further
2334 -- distinguish these cases, note that the scope of a task entry or
2335 -- protected operation is type of the prefix.
2337 -- The prefix could be an overloaded function call that returns both
2338 -- kinds of operations. This overloading pathology is left to the
2339 -- dedicated reader ???
2342 T : constant Entity_Id := Etype (Prefix (Nam));
2351 Is_Tagged_Type (Designated_Type (T))))
2352 and then Scope (Entity (Selector_Name (Nam))) /= T
2354 Analyze_Renamed_Primitive_Operation
2355 (N, New_S, Present (Rename_Spec));
2359 -- Renamed entity is an entry or protected operation. For those
2360 -- cases an explicit body is built (at the point of freezing of
2361 -- this entity) that contains a call to the renamed entity.
2363 -- This is not allowed for renaming as body if the renamed
2364 -- spec is already frozen (see RM 8.5.4(5) for details).
2366 if Present (Rename_Spec)
2367 and then Is_Frozen (Rename_Spec)
2370 ("renaming-as-body cannot rename entry as subprogram", N);
2372 ("\since & is already frozen (RM 8.5.4(5))",
2375 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2382 elsif Nkind (Nam) = N_Explicit_Dereference then
2384 -- Renamed entity is designated by access_to_subprogram expression.
2385 -- Must build body to encapsulate call, as in the entry case.
2387 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2390 elsif Nkind (Nam) = N_Indexed_Component then
2391 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
2394 elsif Nkind (Nam) = N_Character_Literal then
2395 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
2398 elsif not Is_Entity_Name (Nam)
2399 or else not Is_Overloadable (Entity (Nam))
2401 -- Do not mention the renaming if it comes from an instance
2403 if not Is_Actual then
2404 Error_Msg_N ("expect valid subprogram name in renaming", N);
2406 Error_Msg_NE ("no visible subprogram for formal&", N, Nam);
2412 -- Find the renamed entity that matches the given specification. Disable
2413 -- Ada_83 because there is no requirement of full conformance between
2414 -- renamed entity and new entity, even though the same circuit is used.
2416 -- This is a bit of a kludge, which introduces a really irregular use of
2417 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2420 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2421 Ada_Version_Explicit := Ada_Version;
2424 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2426 -- The visible operation may be an inherited abstract operation that
2427 -- was overridden in the private part, in which case a call will
2428 -- dispatch to the overriding operation. Use the overriding one in
2429 -- the renaming declaration, to prevent spurious errors below.
2431 if Is_Overloadable (Old_S)
2432 and then Is_Abstract_Subprogram (Old_S)
2433 and then No (DTC_Entity (Old_S))
2434 and then Present (Alias (Old_S))
2435 and then not Is_Abstract_Subprogram (Alias (Old_S))
2436 and then Present (Overridden_Operation (Alias (Old_S)))
2438 Old_S := Alias (Old_S);
2441 -- When the renamed subprogram is overloaded and used as an actual
2442 -- of a generic, its entity is set to the first available homonym.
2443 -- We must first disambiguate the name, then set the proper entity.
2445 if Is_Actual and then Is_Overloaded (Nam) then
2446 Set_Entity (Nam, Old_S);
2450 -- Most common case: subprogram renames subprogram. No body is generated
2451 -- in this case, so we must indicate the declaration is complete as is.
2452 -- and inherit various attributes of the renamed subprogram.
2454 if No (Rename_Spec) then
2455 Set_Has_Completion (New_S);
2456 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2457 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2458 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2460 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2461 -- between a subprogram and its correct renaming.
2463 -- Note: the Any_Id check is a guard that prevents compiler crashes
2464 -- when performing a null exclusion check between a renaming and a
2465 -- renamed subprogram that has been found to be illegal.
2467 if Ada_Version >= Ada_2005
2468 and then Entity (Nam) /= Any_Id
2470 Check_Null_Exclusion
2472 Sub => Entity (Nam));
2475 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2476 -- overriding. The flag Requires_Overriding is set very selectively
2477 -- and misses some other illegal cases. The additional conditions
2478 -- checked below are sufficient but not necessary ???
2480 -- The rule does not apply to the renaming generated for an actual
2481 -- subprogram in an instance.
2486 -- Guard against previous errors, and omit renamings of predefined
2489 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
2492 elsif Requires_Overriding (Old_S)
2494 (Is_Abstract_Subprogram (Old_S)
2495 and then Present (Find_Dispatching_Type (Old_S))
2497 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2500 ("renamed entity cannot be "
2501 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2505 if Old_S /= Any_Id then
2506 if Is_Actual and then From_Default (N) then
2508 -- This is an implicit reference to the default actual
2510 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2513 Generate_Reference (Old_S, Nam);
2516 -- For a renaming-as-body, require subtype conformance, but if the
2517 -- declaration being completed has not been frozen, then inherit the
2518 -- convention of the renamed subprogram prior to checking conformance
2519 -- (unless the renaming has an explicit convention established; the
2520 -- rule stated in the RM doesn't seem to address this ???).
2522 if Present (Rename_Spec) then
2523 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2524 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2526 if not Is_Frozen (Rename_Spec) then
2527 if not Has_Convention_Pragma (Rename_Spec) then
2528 Set_Convention (New_S, Convention (Old_S));
2531 if Ekind (Old_S) /= E_Operator then
2532 Check_Mode_Conformant (New_S, Old_S, Spec);
2535 if Original_Subprogram (Old_S) = Rename_Spec then
2536 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2539 Check_Subtype_Conformant (New_S, Old_S, Spec);
2542 Check_Frozen_Renaming (N, Rename_Spec);
2544 -- Check explicitly that renamed entity is not intrinsic, because
2545 -- in a generic the renamed body is not built. In this case,
2546 -- the renaming_as_body is a completion.
2548 if Inside_A_Generic then
2549 if Is_Frozen (Rename_Spec)
2550 and then Is_Intrinsic_Subprogram (Old_S)
2553 ("subprogram in renaming_as_body cannot be intrinsic",
2557 Set_Has_Completion (Rename_Spec);
2560 elsif Ekind (Old_S) /= E_Operator then
2562 -- If this a defaulted subprogram for a class-wide actual there is
2563 -- no check for mode conformance, given that the signatures don't
2564 -- match (the source mentions T but the actual mentions T'Class).
2569 Check_Mode_Conformant (New_S, Old_S);
2573 and then Error_Posted (New_S)
2575 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2579 if No (Rename_Spec) then
2581 -- The parameter profile of the new entity is that of the renamed
2582 -- entity: the subtypes given in the specification are irrelevant.
2584 Inherit_Renamed_Profile (New_S, Old_S);
2586 -- A call to the subprogram is transformed into a call to the
2587 -- renamed entity. This is transitive if the renamed entity is
2588 -- itself a renaming.
2590 if Present (Alias (Old_S)) then
2591 Set_Alias (New_S, Alias (Old_S));
2593 Set_Alias (New_S, Old_S);
2596 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2597 -- renaming as body, since the entity in this case is not an
2598 -- intrinsic (it calls an intrinsic, but we have a real body for
2599 -- this call, and it is in this body that the required intrinsic
2600 -- processing will take place).
2602 -- Also, if this is a renaming of inequality, the renamed operator
2603 -- is intrinsic, but what matters is the corresponding equality
2604 -- operator, which may be user-defined.
2606 Set_Is_Intrinsic_Subprogram
2608 Is_Intrinsic_Subprogram (Old_S)
2610 (Chars (Old_S) /= Name_Op_Ne
2611 or else Ekind (Old_S) = E_Operator
2613 Is_Intrinsic_Subprogram
2614 (Corresponding_Equality (Old_S))));
2616 if Ekind (Alias (New_S)) = E_Operator then
2617 Set_Has_Delayed_Freeze (New_S, False);
2620 -- If the renaming corresponds to an association for an abstract
2621 -- formal subprogram, then various attributes must be set to
2622 -- indicate that the renaming is an abstract dispatching operation
2623 -- with a controlling type.
2625 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2627 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2628 -- see it as corresponding to a generic association for a
2629 -- formal abstract subprogram
2631 Set_Is_Abstract_Subprogram (New_S);
2634 New_S_Ctrl_Type : constant Entity_Id :=
2635 Find_Dispatching_Type (New_S);
2636 Old_S_Ctrl_Type : constant Entity_Id :=
2637 Find_Dispatching_Type (Old_S);
2640 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2642 ("actual must be dispatching subprogram for type&",
2643 Nam, New_S_Ctrl_Type);
2646 Set_Is_Dispatching_Operation (New_S);
2647 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2649 -- If the actual in the formal subprogram is itself a
2650 -- formal abstract subprogram association, there's no
2651 -- dispatch table component or position to inherit.
2653 if Present (DTC_Entity (Old_S)) then
2654 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2655 Set_DT_Position (New_S, DT_Position (Old_S));
2663 and then (Old_S = New_S
2664 or else (Nkind (Nam) /= N_Expanded_Name
2665 and then Chars (Old_S) = Chars (New_S)))
2667 Error_Msg_N ("subprogram cannot rename itself", N);
2670 Set_Convention (New_S, Convention (Old_S));
2672 if Is_Abstract_Subprogram (Old_S) then
2673 if Present (Rename_Spec) then
2675 ("a renaming-as-body cannot rename an abstract subprogram",
2677 Set_Has_Completion (Rename_Spec);
2679 Set_Is_Abstract_Subprogram (New_S);
2683 Check_Library_Unit_Renaming (N, Old_S);
2685 -- Pathological case: procedure renames entry in the scope of its
2686 -- task. Entry is given by simple name, but body must be built for
2687 -- procedure. Of course if called it will deadlock.
2689 if Ekind (Old_S) = E_Entry then
2690 Set_Has_Completion (New_S, False);
2691 Set_Alias (New_S, Empty);
2695 Freeze_Before (N, Old_S);
2696 Set_Has_Delayed_Freeze (New_S, False);
2697 Freeze_Before (N, New_S);
2699 -- An abstract subprogram is only allowed as an actual in the case
2700 -- where the formal subprogram is also abstract.
2702 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2703 and then Is_Abstract_Subprogram (Old_S)
2704 and then not Is_Abstract_Subprogram (Formal_Spec)
2707 ("abstract subprogram not allowed as generic actual", Nam);
2712 -- A common error is to assume that implicit operators for types are
2713 -- defined in Standard, or in the scope of a subtype. In those cases
2714 -- where the renamed entity is given with an expanded name, it is
2715 -- worth mentioning that operators for the type are not declared in
2716 -- the scope given by the prefix.
2718 if Nkind (Nam) = N_Expanded_Name
2719 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2720 and then Scope (Entity (Nam)) = Standard_Standard
2723 T : constant Entity_Id :=
2724 Base_Type (Etype (First_Formal (New_S)));
2726 Error_Msg_Node_2 := Prefix (Nam);
2728 ("operator for type& is not declared in&", Prefix (Nam), T);
2733 ("no visible subprogram matches the specification for&",
2737 if Present (Candidate_Renaming) then
2744 F1 := First_Formal (Candidate_Renaming);
2745 F2 := First_Formal (New_S);
2746 T1 := First_Subtype (Etype (F1));
2748 while Present (F1) and then Present (F2) loop
2753 if Present (F1) and then Present (Default_Value (F1)) then
2754 if Present (Next_Formal (F1)) then
2756 ("\missing specification for &" &
2757 " and other formals with defaults", Spec, F1);
2760 ("\missing specification for &", Spec, F1);
2764 if Nkind (Nam) = N_Operator_Symbol
2765 and then From_Default (N)
2767 Error_Msg_Node_2 := T1;
2769 ("default & on & is not directly visible",
2776 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2777 -- controlling access parameters are known non-null for the renamed
2778 -- subprogram. Test also applies to a subprogram instantiation that
2779 -- is dispatching. Test is skipped if some previous error was detected
2780 -- that set Old_S to Any_Id.
2782 if Ada_Version >= Ada_2005
2783 and then Old_S /= Any_Id
2784 and then not Is_Dispatching_Operation (Old_S)
2785 and then Is_Dispatching_Operation (New_S)
2792 Old_F := First_Formal (Old_S);
2793 New_F := First_Formal (New_S);
2794 while Present (Old_F) loop
2795 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2796 and then Is_Controlling_Formal (New_F)
2797 and then not Can_Never_Be_Null (Old_F)
2799 Error_Msg_N ("access parameter is controlling,", New_F);
2801 ("\corresponding parameter of& "
2802 & "must be explicitly null excluding", New_F, Old_S);
2805 Next_Formal (Old_F);
2806 Next_Formal (New_F);
2811 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2812 -- is to warn if an operator is being renamed as a different operator.
2813 -- If the operator is predefined, examine the kind of the entity, not
2814 -- the abbreviated declaration in Standard.
2816 if Comes_From_Source (N)
2817 and then Present (Old_S)
2819 (Nkind (Old_S) = N_Defining_Operator_Symbol
2820 or else Ekind (Old_S) = E_Operator)
2821 and then Nkind (New_S) = N_Defining_Operator_Symbol
2822 and then Chars (Old_S) /= Chars (New_S)
2825 ("?& is being renamed as a different operator", N, Old_S);
2828 -- Check for renaming of obsolescent subprogram
2830 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
2832 -- Another warning or some utility: if the new subprogram as the same
2833 -- name as the old one, the old one is not hidden by an outer homograph,
2834 -- the new one is not a public symbol, and the old one is otherwise
2835 -- directly visible, the renaming is superfluous.
2837 if Chars (Old_S) = Chars (New_S)
2838 and then Comes_From_Source (N)
2839 and then Scope (Old_S) /= Standard_Standard
2840 and then Warn_On_Redundant_Constructs
2842 (Is_Immediately_Visible (Old_S)
2843 or else Is_Potentially_Use_Visible (Old_S))
2844 and then Is_Overloadable (Current_Scope)
2845 and then Chars (Current_Scope) /= Chars (Old_S)
2848 ("?redundant renaming, entity is directly visible", Name (N));
2851 Ada_Version := Save_AV;
2852 Ada_Version_Explicit := Save_AV_Exp;
2853 end Analyze_Subprogram_Renaming;
2855 -------------------------
2856 -- Analyze_Use_Package --
2857 -------------------------
2859 -- Resolve the package names in the use clause, and make all the visible
2860 -- entities defined in the package potentially use-visible. If the package
2861 -- is already in use from a previous use clause, its visible entities are
2862 -- already use-visible. In that case, mark the occurrence as a redundant
2863 -- use. If the package is an open scope, i.e. if the use clause occurs
2864 -- within the package itself, ignore it.
2866 procedure Analyze_Use_Package (N : Node_Id) is
2867 Pack_Name : Node_Id;
2870 -- Start of processing for Analyze_Use_Package
2873 Check_SPARK_Restriction ("use clause is not allowed", N);
2875 Set_Hidden_By_Use_Clause (N, No_Elist);
2877 -- Use clause not allowed in a spec of a predefined package declaration
2878 -- except that packages whose file name starts a-n are OK (these are
2879 -- children of Ada.Numerics, which are never loaded by Rtsfind).
2881 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2882 and then Name_Buffer (1 .. 3) /= "a-n"
2884 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2886 Error_Msg_N ("use clause not allowed in predefined spec", N);
2889 -- Chain clause to list of use clauses in current scope
2891 if Nkind (Parent (N)) /= N_Compilation_Unit then
2892 Chain_Use_Clause (N);
2895 -- Loop through package names to identify referenced packages
2897 Pack_Name := First (Names (N));
2898 while Present (Pack_Name) loop
2899 Analyze (Pack_Name);
2901 if Nkind (Parent (N)) = N_Compilation_Unit
2902 and then Nkind (Pack_Name) = N_Expanded_Name
2908 Pref := Prefix (Pack_Name);
2909 while Nkind (Pref) = N_Expanded_Name loop
2910 Pref := Prefix (Pref);
2913 if Entity (Pref) = Standard_Standard then
2915 ("predefined package Standard cannot appear"
2916 & " in a context clause", Pref);
2924 -- Loop through package names to mark all entities as potentially
2927 Pack_Name := First (Names (N));
2928 while Present (Pack_Name) loop
2929 if Is_Entity_Name (Pack_Name) then
2930 Pack := Entity (Pack_Name);
2932 if Ekind (Pack) /= E_Package
2933 and then Etype (Pack) /= Any_Type
2935 if Ekind (Pack) = E_Generic_Package then
2936 Error_Msg_N -- CODEFIX
2937 ("a generic package is not allowed in a use clause",
2940 Error_Msg_N ("& is not a usable package", Pack_Name);
2944 if Nkind (Parent (N)) = N_Compilation_Unit then
2945 Check_In_Previous_With_Clause (N, Pack_Name);
2948 if Applicable_Use (Pack_Name) then
2949 Use_One_Package (Pack, N);
2953 -- Report error because name denotes something other than a package
2956 Error_Msg_N ("& is not a package", Pack_Name);
2961 end Analyze_Use_Package;
2963 ----------------------
2964 -- Analyze_Use_Type --
2965 ----------------------
2967 procedure Analyze_Use_Type (N : Node_Id) is
2972 Set_Hidden_By_Use_Clause (N, No_Elist);
2974 -- Chain clause to list of use clauses in current scope
2976 if Nkind (Parent (N)) /= N_Compilation_Unit then
2977 Chain_Use_Clause (N);
2980 -- If the Used_Operations list is already initialized, the clause has
2981 -- been analyzed previously, and it is begin reinstalled, for example
2982 -- when the clause appears in a package spec and we are compiling the
2983 -- corresponding package body. In that case, make the entities on the
2984 -- existing list use_visible, and mark the corresponding types In_Use.
2986 if Present (Used_Operations (N)) then
2992 Mark := First (Subtype_Marks (N));
2993 while Present (Mark) loop
2994 Use_One_Type (Mark, Installed => True);
2998 Elmt := First_Elmt (Used_Operations (N));
2999 while Present (Elmt) loop
3000 Set_Is_Potentially_Use_Visible (Node (Elmt));
3008 -- Otherwise, create new list and attach to it the operations that
3009 -- are made use-visible by the clause.
3011 Set_Used_Operations (N, New_Elmt_List);
3012 Id := First (Subtype_Marks (N));
3013 while Present (Id) loop
3017 if E /= Any_Type then
3020 if Nkind (Parent (N)) = N_Compilation_Unit then
3021 if Nkind (Id) = N_Identifier then
3022 Error_Msg_N ("type is not directly visible", Id);
3024 elsif Is_Child_Unit (Scope (E))
3025 and then Scope (E) /= System_Aux_Id
3027 Check_In_Previous_With_Clause (N, Prefix (Id));
3032 -- If the use_type_clause appears in a compilation unit context,
3033 -- check whether it comes from a unit that may appear in a
3034 -- limited_with_clause, for a better error message.
3036 if Nkind (Parent (N)) = N_Compilation_Unit
3037 and then Nkind (Id) /= N_Identifier
3043 function Mentioned (Nam : Node_Id) return Boolean;
3044 -- Check whether the prefix of expanded name for the type
3045 -- appears in the prefix of some limited_with_clause.
3051 function Mentioned (Nam : Node_Id) return Boolean is
3053 return Nkind (Name (Item)) = N_Selected_Component
3055 Chars (Prefix (Name (Item))) = Chars (Nam);
3059 Pref := Prefix (Id);
3060 Item := First (Context_Items (Parent (N)));
3062 while Present (Item) and then Item /= N loop
3063 if Nkind (Item) = N_With_Clause
3064 and then Limited_Present (Item)
3065 and then Mentioned (Pref)
3068 (Get_Msg_Id, "premature usage of incomplete type");
3079 end Analyze_Use_Type;
3081 --------------------
3082 -- Applicable_Use --
3083 --------------------
3085 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
3086 Pack : constant Entity_Id := Entity (Pack_Name);
3089 if In_Open_Scopes (Pack) then
3090 if Warn_On_Redundant_Constructs
3091 and then Pack = Current_Scope
3093 Error_Msg_NE -- CODEFIX
3094 ("& is already use-visible within itself?", Pack_Name, Pack);
3099 elsif In_Use (Pack) then
3100 Note_Redundant_Use (Pack_Name);
3103 elsif Present (Renamed_Object (Pack))
3104 and then In_Use (Renamed_Object (Pack))
3106 Note_Redundant_Use (Pack_Name);
3114 ------------------------
3115 -- Attribute_Renaming --
3116 ------------------------
3118 procedure Attribute_Renaming (N : Node_Id) is
3119 Loc : constant Source_Ptr := Sloc (N);
3120 Nam : constant Node_Id := Name (N);
3121 Spec : constant Node_Id := Specification (N);
3122 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
3123 Aname : constant Name_Id := Attribute_Name (Nam);
3125 Form_Num : Nat := 0;
3126 Expr_List : List_Id := No_List;
3128 Attr_Node : Node_Id;
3129 Body_Node : Node_Id;
3130 Param_Spec : Node_Id;
3133 Generate_Definition (New_S);
3135 -- This procedure is called in the context of subprogram renaming, and
3136 -- thus the attribute must be one that is a subprogram. All of those
3137 -- have at least one formal parameter, with the singular exception of
3138 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
3141 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
3142 if Aname /= Name_AST_Entry then
3144 ("subprogram renaming an attribute must have formals", N);
3149 Param_Spec := First (Parameter_Specifications (Spec));
3150 while Present (Param_Spec) loop
3151 Form_Num := Form_Num + 1;
3153 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
3154 Find_Type (Parameter_Type (Param_Spec));
3156 -- The profile of the new entity denotes the base type (s) of
3157 -- the types given in the specification. For access parameters
3158 -- there are no subtypes involved.
3160 Rewrite (Parameter_Type (Param_Spec),
3162 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
3165 if No (Expr_List) then
3166 Expr_List := New_List;
3169 Append_To (Expr_List,
3170 Make_Identifier (Loc,
3171 Chars => Chars (Defining_Identifier (Param_Spec))));
3173 -- The expressions in the attribute reference are not freeze
3174 -- points. Neither is the attribute as a whole, see below.
3176 Set_Must_Not_Freeze (Last (Expr_List));
3181 -- Immediate error if too many formals. Other mismatches in number or
3182 -- types of parameters are detected when we analyze the body of the
3183 -- subprogram that we construct.
3185 if Form_Num > 2 then
3186 Error_Msg_N ("too many formals for attribute", N);
3188 -- Error if the attribute reference has expressions that look like
3189 -- formal parameters.
3191 elsif Present (Expressions (Nam)) then
3192 Error_Msg_N ("illegal expressions in attribute reference", Nam);
3195 Aname = Name_Compose or else
3196 Aname = Name_Exponent or else
3197 Aname = Name_Leading_Part or else
3198 Aname = Name_Pos or else
3199 Aname = Name_Round or else
3200 Aname = Name_Scaling or else
3203 if Nkind (N) = N_Subprogram_Renaming_Declaration
3204 and then Present (Corresponding_Formal_Spec (N))
3207 ("generic actual cannot be attribute involving universal type",
3211 ("attribute involving a universal type cannot be renamed",
3216 -- AST_Entry is an odd case. It doesn't really make much sense to allow
3217 -- it to be renamed, but that's the DEC rule, so we have to do it right.
3218 -- The point is that the AST_Entry call should be made now, and what the
3219 -- function will return is the returned value.
3221 -- Note that there is no Expr_List in this case anyway
3223 if Aname = Name_AST_Entry then
3225 Ent : constant Entity_Id := Make_Temporary (Loc, 'R', Nam);
3230 Make_Object_Declaration (Loc,
3231 Defining_Identifier => Ent,
3232 Object_Definition =>
3233 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
3235 Constant_Present => True);
3237 Set_Assignment_OK (Decl, True);
3238 Insert_Action (N, Decl);
3239 Attr_Node := Make_Identifier (Loc, Chars (Ent));
3242 -- For all other attributes, we rewrite the attribute node to have
3243 -- a list of expressions corresponding to the subprogram formals.
3244 -- A renaming declaration is not a freeze point, and the analysis of
3245 -- the attribute reference should not freeze the type of the prefix.
3249 Make_Attribute_Reference (Loc,
3250 Prefix => Prefix (Nam),
3251 Attribute_Name => Aname,
3252 Expressions => Expr_List);
3254 Set_Must_Not_Freeze (Attr_Node);
3255 Set_Must_Not_Freeze (Prefix (Nam));
3258 -- Case of renaming a function
3260 if Nkind (Spec) = N_Function_Specification then
3261 if Is_Procedure_Attribute_Name (Aname) then
3262 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
3266 Find_Type (Result_Definition (Spec));
3267 Rewrite (Result_Definition (Spec),
3269 Base_Type (Entity (Result_Definition (Spec))), Loc));
3272 Make_Subprogram_Body (Loc,
3273 Specification => Spec,
3274 Declarations => New_List,
3275 Handled_Statement_Sequence =>
3276 Make_Handled_Sequence_Of_Statements (Loc,
3277 Statements => New_List (
3278 Make_Simple_Return_Statement (Loc,
3279 Expression => Attr_Node))));
3281 -- Case of renaming a procedure
3284 if not Is_Procedure_Attribute_Name (Aname) then
3285 Error_Msg_N ("attribute can only be renamed as function", Nam);
3290 Make_Subprogram_Body (Loc,
3291 Specification => Spec,
3292 Declarations => New_List,
3293 Handled_Statement_Sequence =>
3294 Make_Handled_Sequence_Of_Statements (Loc,
3295 Statements => New_List (Attr_Node)));
3298 -- In case of tagged types we add the body of the generated function to
3299 -- the freezing actions of the type (because in the general case such
3300 -- type is still not frozen). We exclude from this processing generic
3301 -- formal subprograms found in instantiations and AST_Entry renamings.
3303 -- We must exclude VM targets and restricted run-time libraries because
3304 -- entity AST_Handler is defined in package System.Aux_Dec which is not
3305 -- available in those platforms. Note that we cannot use the function
3306 -- Restricted_Profile (instead of Configurable_Run_Time_Mode) because
3307 -- the ZFP run-time library is not defined as a profile, and we do not
3308 -- want to deal with AST_Handler in ZFP mode.
3310 if VM_Target = No_VM
3311 and then not Configurable_Run_Time_Mode
3312 and then not Present (Corresponding_Formal_Spec (N))
3313 and then Etype (Nam) /= RTE (RE_AST_Handler)
3316 P : constant Entity_Id := Prefix (Nam);
3321 if Is_Tagged_Type (Etype (P)) then
3322 Ensure_Freeze_Node (Etype (P));
3323 Append_Freeze_Action (Etype (P), Body_Node);
3325 Rewrite (N, Body_Node);
3327 Set_Etype (New_S, Base_Type (Etype (New_S)));
3331 -- Generic formal subprograms or AST_Handler renaming
3334 Rewrite (N, Body_Node);
3336 Set_Etype (New_S, Base_Type (Etype (New_S)));
3339 if Is_Compilation_Unit (New_S) then
3341 ("a library unit can only rename another library unit", N);
3344 -- We suppress elaboration warnings for the resulting entity, since
3345 -- clearly they are not needed, and more particularly, in the case
3346 -- of a generic formal subprogram, the resulting entity can appear
3347 -- after the instantiation itself, and thus look like a bogus case
3348 -- of access before elaboration.
3350 Set_Suppress_Elaboration_Warnings (New_S);
3352 end Attribute_Renaming;
3354 ----------------------
3355 -- Chain_Use_Clause --
3356 ----------------------
3358 procedure Chain_Use_Clause (N : Node_Id) is
3360 Level : Int := Scope_Stack.Last;
3363 if not Is_Compilation_Unit (Current_Scope)
3364 or else not Is_Child_Unit (Current_Scope)
3366 null; -- Common case
3368 elsif Defining_Entity (Parent (N)) = Current_Scope then
3369 null; -- Common case for compilation unit
3372 -- If declaration appears in some other scope, it must be in some
3373 -- parent unit when compiling a child.
3375 Pack := Defining_Entity (Parent (N));
3376 if not In_Open_Scopes (Pack) then
3377 null; -- default as well
3380 -- Find entry for parent unit in scope stack
3382 while Scope_Stack.Table (Level).Entity /= Pack loop
3388 Set_Next_Use_Clause (N,
3389 Scope_Stack.Table (Level).First_Use_Clause);
3390 Scope_Stack.Table (Level).First_Use_Clause := N;
3391 end Chain_Use_Clause;
3393 ---------------------------
3394 -- Check_Frozen_Renaming --
3395 ---------------------------
3397 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
3403 and then not Has_Completion (Subp)
3407 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
3409 if Is_Entity_Name (Name (N)) then
3410 Old_S := Entity (Name (N));
3412 if not Is_Frozen (Old_S)
3413 and then Operating_Mode /= Check_Semantics
3415 Append_Freeze_Action (Old_S, B_Node);
3417 Insert_After (N, B_Node);
3421 if Is_Intrinsic_Subprogram (Old_S)
3422 and then not In_Instance
3425 ("subprogram used in renaming_as_body cannot be intrinsic",
3430 Insert_After (N, B_Node);
3434 end Check_Frozen_Renaming;
3436 -------------------------------
3437 -- Set_Entity_Or_Discriminal --
3438 -------------------------------
3440 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
3444 -- If the entity is not a discriminant, or else expansion is disabled,
3445 -- simply set the entity.
3447 if not In_Spec_Expression
3448 or else Ekind (E) /= E_Discriminant
3449 or else Inside_A_Generic
3451 Set_Entity_With_Style_Check (N, E);
3453 -- The replacement of a discriminant by the corresponding discriminal
3454 -- is not done for a task discriminant that appears in a default
3455 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
3456 -- for details on their handling.
3458 elsif Is_Concurrent_Type (Scope (E)) then
3462 and then not Nkind_In (P, N_Parameter_Specification,
3463 N_Component_Declaration)
3469 and then Nkind (P) = N_Parameter_Specification
3474 Set_Entity (N, Discriminal (E));
3477 -- Otherwise, this is a discriminant in a context in which
3478 -- it is a reference to the corresponding parameter of the
3479 -- init proc for the enclosing type.
3482 Set_Entity (N, Discriminal (E));
3484 end Set_Entity_Or_Discriminal;
3486 -----------------------------------
3487 -- Check_In_Previous_With_Clause --
3488 -----------------------------------
3490 procedure Check_In_Previous_With_Clause
3494 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3499 Item := First (Context_Items (Parent (N)));
3501 while Present (Item)
3504 if Nkind (Item) = N_With_Clause
3506 -- Protect the frontend against previous critical errors
3508 and then Nkind (Name (Item)) /= N_Selected_Component
3509 and then Entity (Name (Item)) = Pack
3513 -- Find root library unit in with_clause
3515 while Nkind (Par) = N_Expanded_Name loop
3516 Par := Prefix (Par);
3519 if Is_Child_Unit (Entity (Original_Node (Par))) then
3520 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
3529 -- On exit, package is not mentioned in a previous with_clause.
3530 -- Check if its prefix is.
3532 if Nkind (Nam) = N_Expanded_Name then
3533 Check_In_Previous_With_Clause (N, Prefix (Nam));
3535 elsif Pack /= Any_Id then
3536 Error_Msg_NE ("& is not visible", Nam, Pack);
3538 end Check_In_Previous_With_Clause;
3540 ---------------------------------
3541 -- Check_Library_Unit_Renaming --
3542 ---------------------------------
3544 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3548 if Nkind (Parent (N)) /= N_Compilation_Unit then
3551 -- Check for library unit. Note that we used to check for the scope
3552 -- being Standard here, but that was wrong for Standard itself.
3554 elsif not Is_Compilation_Unit (Old_E)
3555 and then not Is_Child_Unit (Old_E)
3557 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3559 -- Entities defined in Standard (operators and boolean literals) cannot
3560 -- be renamed as library units.
3562 elsif Scope (Old_E) = Standard_Standard
3563 and then Sloc (Old_E) = Standard_Location
3565 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3567 elsif Present (Parent_Spec (N))
3568 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3569 and then not Is_Child_Unit (Old_E)
3572 ("renamed unit must be a child unit of generic parent", Name (N));
3574 elsif Nkind (N) in N_Generic_Renaming_Declaration
3575 and then Nkind (Name (N)) = N_Expanded_Name
3576 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3577 and then Is_Generic_Unit (Old_E)
3580 ("renamed generic unit must be a library unit", Name (N));
3582 elsif Is_Package_Or_Generic_Package (Old_E) then
3584 -- Inherit categorization flags
3586 New_E := Defining_Entity (N);
3587 Set_Is_Pure (New_E, Is_Pure (Old_E));
3588 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3589 Set_Is_Remote_Call_Interface (New_E,
3590 Is_Remote_Call_Interface (Old_E));
3591 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3592 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3594 end Check_Library_Unit_Renaming;
3600 procedure End_Scope is
3606 Id := First_Entity (Current_Scope);
3607 while Present (Id) loop
3608 -- An entity in the current scope is not necessarily the first one
3609 -- on its homonym chain. Find its predecessor if any,
3610 -- If it is an internal entity, it will not be in the visibility
3611 -- chain altogether, and there is nothing to unchain.
3613 if Id /= Current_Entity (Id) then
3614 Prev := Current_Entity (Id);
3615 while Present (Prev)
3616 and then Present (Homonym (Prev))
3617 and then Homonym (Prev) /= Id
3619 Prev := Homonym (Prev);
3622 -- Skip to end of loop if Id is not in the visibility chain
3624 if No (Prev) or else Homonym (Prev) /= Id then
3632 Set_Is_Immediately_Visible (Id, False);
3634 Outer := Homonym (Id);
3635 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3636 Outer := Homonym (Outer);
3639 -- Reset homonym link of other entities, but do not modify link
3640 -- between entities in current scope, so that the back-end can have
3641 -- a proper count of local overloadings.
3644 Set_Name_Entity_Id (Chars (Id), Outer);
3646 elsif Scope (Prev) /= Scope (Id) then
3647 Set_Homonym (Prev, Outer);
3654 -- If the scope generated freeze actions, place them before the
3655 -- current declaration and analyze them. Type declarations and
3656 -- the bodies of initialization procedures can generate such nodes.
3657 -- We follow the parent chain until we reach a list node, which is
3658 -- the enclosing list of declarations. If the list appears within
3659 -- a protected definition, move freeze nodes outside the protected
3663 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3667 L : constant List_Id := Scope_Stack.Table
3668 (Scope_Stack.Last).Pending_Freeze_Actions;
3671 if Is_Itype (Current_Scope) then
3672 Decl := Associated_Node_For_Itype (Current_Scope);
3674 Decl := Parent (Current_Scope);
3679 while not (Is_List_Member (Decl))
3680 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3683 Decl := Parent (Decl);
3686 Insert_List_Before_And_Analyze (Decl, L);
3695 ---------------------
3696 -- End_Use_Clauses --
3697 ---------------------
3699 procedure End_Use_Clauses (Clause : Node_Id) is
3703 -- Remove Use_Type clauses first, because they affect the
3704 -- visibility of operators in subsequent used packages.
3707 while Present (U) loop
3708 if Nkind (U) = N_Use_Type_Clause then
3712 Next_Use_Clause (U);
3716 while Present (U) loop
3717 if Nkind (U) = N_Use_Package_Clause then
3718 End_Use_Package (U);
3721 Next_Use_Clause (U);
3723 end End_Use_Clauses;
3725 ---------------------
3726 -- End_Use_Package --
3727 ---------------------
3729 procedure End_Use_Package (N : Node_Id) is
3730 Pack_Name : Node_Id;
3735 function Is_Primitive_Operator_In_Use
3737 F : Entity_Id) return Boolean;
3738 -- Check whether Op is a primitive operator of a use-visible type
3740 ----------------------------------
3741 -- Is_Primitive_Operator_In_Use --
3742 ----------------------------------
3744 function Is_Primitive_Operator_In_Use
3746 F : Entity_Id) return Boolean
3748 T : constant Entity_Id := Base_Type (Etype (F));
3750 return In_Use (T) and then Scope (T) = Scope (Op);
3751 end Is_Primitive_Operator_In_Use;
3753 -- Start of processing for End_Use_Package
3756 Pack_Name := First (Names (N));
3757 while Present (Pack_Name) loop
3759 -- Test that Pack_Name actually denotes a package before processing
3761 if Is_Entity_Name (Pack_Name)
3762 and then Ekind (Entity (Pack_Name)) = E_Package
3764 Pack := Entity (Pack_Name);
3766 if In_Open_Scopes (Pack) then
3769 elsif not Redundant_Use (Pack_Name) then
3770 Set_In_Use (Pack, False);
3771 Set_Current_Use_Clause (Pack, Empty);
3773 Id := First_Entity (Pack);
3774 while Present (Id) loop
3776 -- Preserve use-visibility of operators that are primitive
3777 -- operators of a type that is use-visible through an active
3780 if Nkind (Id) = N_Defining_Operator_Symbol
3782 (Is_Primitive_Operator_In_Use
3783 (Id, First_Formal (Id))
3785 (Present (Next_Formal (First_Formal (Id)))
3787 Is_Primitive_Operator_In_Use
3788 (Id, Next_Formal (First_Formal (Id)))))
3793 Set_Is_Potentially_Use_Visible (Id, False);
3796 if Is_Private_Type (Id)
3797 and then Present (Full_View (Id))
3799 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3805 if Present (Renamed_Object (Pack)) then
3806 Set_In_Use (Renamed_Object (Pack), False);
3807 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3810 if Chars (Pack) = Name_System
3811 and then Scope (Pack) = Standard_Standard
3812 and then Present_System_Aux
3814 Id := First_Entity (System_Aux_Id);
3815 while Present (Id) loop
3816 Set_Is_Potentially_Use_Visible (Id, False);
3818 if Is_Private_Type (Id)
3819 and then Present (Full_View (Id))
3821 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3827 Set_In_Use (System_Aux_Id, False);
3831 Set_Redundant_Use (Pack_Name, False);
3838 if Present (Hidden_By_Use_Clause (N)) then
3839 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3840 while Present (Elmt) loop
3842 E : constant Entity_Id := Node (Elmt);
3845 -- Reset either Use_Visibility or Direct_Visibility, depending
3846 -- on how the entity was hidden by the use clause.
3848 if In_Use (Scope (E))
3849 and then Used_As_Generic_Actual (Scope (E))
3851 Set_Is_Potentially_Use_Visible (Node (Elmt));
3853 Set_Is_Immediately_Visible (Node (Elmt));
3860 Set_Hidden_By_Use_Clause (N, No_Elist);
3862 end End_Use_Package;
3868 procedure End_Use_Type (N : Node_Id) is
3873 -- Start of processing for End_Use_Type
3876 Id := First (Subtype_Marks (N));
3877 while Present (Id) loop
3879 -- A call to Rtsfind may occur while analyzing a use_type clause,
3880 -- in which case the type marks are not resolved yet, and there is
3881 -- nothing to remove.
3883 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
3889 if T = Any_Type or else From_With_Type (T) then
3892 -- Note that the use_type clause may mention a subtype of the type
3893 -- whose primitive operations have been made visible. Here as
3894 -- elsewhere, it is the base type that matters for visibility.
3896 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3899 elsif not Redundant_Use (Id) then
3900 Set_In_Use (T, False);
3901 Set_In_Use (Base_Type (T), False);
3902 Set_Current_Use_Clause (T, Empty);
3903 Set_Current_Use_Clause (Base_Type (T), Empty);
3910 if Is_Empty_Elmt_List (Used_Operations (N)) then
3914 Elmt := First_Elmt (Used_Operations (N));
3915 while Present (Elmt) loop
3916 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3922 ----------------------
3923 -- Find_Direct_Name --
3924 ----------------------
3926 procedure Find_Direct_Name (N : Node_Id) is
3931 Inst : Entity_Id := Empty;
3932 -- Enclosing instance, if any
3934 Homonyms : Entity_Id;
3935 -- Saves start of homonym chain
3937 Nvis_Entity : Boolean;
3938 -- Set True to indicate that there is at least one entity on the homonym
3939 -- chain which, while not visible, is visible enough from the user point
3940 -- of view to warrant an error message of "not visible" rather than
3943 Nvis_Is_Private_Subprg : Boolean := False;
3944 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3945 -- effect concerning library subprograms has been detected. Used to
3946 -- generate the precise error message.
3948 function From_Actual_Package (E : Entity_Id) return Boolean;
3949 -- Returns true if the entity is declared in a package that is
3950 -- an actual for a formal package of the current instance. Such an
3951 -- entity requires special handling because it may be use-visible
3952 -- but hides directly visible entities defined outside the instance.
3954 function Is_Actual_Parameter return Boolean;
3955 -- This function checks if the node N is an identifier that is an actual
3956 -- parameter of a procedure call. If so it returns True, otherwise it
3957 -- return False. The reason for this check is that at this stage we do
3958 -- not know what procedure is being called if the procedure might be
3959 -- overloaded, so it is premature to go setting referenced flags or
3960 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3961 -- for that processing
3963 function Known_But_Invisible (E : Entity_Id) return Boolean;
3964 -- This function determines whether the entity E (which is not
3965 -- visible) can reasonably be considered to be known to the writer
3966 -- of the reference. This is a heuristic test, used only for the
3967 -- purposes of figuring out whether we prefer to complain that an
3968 -- entity is undefined or invisible (and identify the declaration
3969 -- of the invisible entity in the latter case). The point here is
3970 -- that we don't want to complain that something is invisible and
3971 -- then point to something entirely mysterious to the writer.
3973 procedure Nvis_Messages;
3974 -- Called if there are no visible entries for N, but there is at least
3975 -- one non-directly visible, or hidden declaration. This procedure
3976 -- outputs an appropriate set of error messages.
3978 procedure Undefined (Nvis : Boolean);
3979 -- This function is called if the current node has no corresponding
3980 -- visible entity or entities. The value set in Msg indicates whether
3981 -- an error message was generated (multiple error messages for the
3982 -- same variable are generally suppressed, see body for details).
3983 -- Msg is True if an error message was generated, False if not. This
3984 -- value is used by the caller to determine whether or not to output
3985 -- additional messages where appropriate. The parameter is set False
3986 -- to get the message "X is undefined", and True to get the message
3987 -- "X is not visible".
3989 -------------------------
3990 -- From_Actual_Package --
3991 -------------------------
3993 function From_Actual_Package (E : Entity_Id) return Boolean is
3994 Scop : constant Entity_Id := Scope (E);
3998 if not In_Instance then
4001 Inst := Current_Scope;
4002 while Present (Inst)
4003 and then Ekind (Inst) /= E_Package
4004 and then not Is_Generic_Instance (Inst)
4006 Inst := Scope (Inst);
4013 Act := First_Entity (Inst);
4014 while Present (Act) loop
4015 if Ekind (Act) = E_Package then
4017 -- Check for end of actuals list
4019 if Renamed_Object (Act) = Inst then
4022 elsif Present (Associated_Formal_Package (Act))
4023 and then Renamed_Object (Act) = Scop
4025 -- Entity comes from (instance of) formal package
4040 end From_Actual_Package;
4042 -------------------------
4043 -- Is_Actual_Parameter --
4044 -------------------------
4046 function Is_Actual_Parameter return Boolean is
4049 Nkind (N) = N_Identifier
4051 (Nkind (Parent (N)) = N_Procedure_Call_Statement
4053 (Nkind (Parent (N)) = N_Parameter_Association
4054 and then N = Explicit_Actual_Parameter (Parent (N))
4055 and then Nkind (Parent (Parent (N))) =
4056 N_Procedure_Call_Statement));
4057 end Is_Actual_Parameter;
4059 -------------------------
4060 -- Known_But_Invisible --
4061 -------------------------
4063 function Known_But_Invisible (E : Entity_Id) return Boolean is
4064 Fname : File_Name_Type;
4067 -- Entities in Standard are always considered to be known
4069 if Sloc (E) <= Standard_Location then
4072 -- An entity that does not come from source is always considered
4073 -- to be unknown, since it is an artifact of code expansion.
4075 elsif not Comes_From_Source (E) then
4078 -- In gnat internal mode, we consider all entities known
4080 elsif GNAT_Mode then
4084 -- Here we have an entity that is not from package Standard, and
4085 -- which comes from Source. See if it comes from an internal file.
4087 Fname := Unit_File_Name (Get_Source_Unit (E));
4089 -- Case of from internal file
4091 if Is_Internal_File_Name (Fname) then
4093 -- Private part entities in internal files are never considered
4094 -- to be known to the writer of normal application code.
4096 if Is_Hidden (E) then
4100 -- Entities from System packages other than System and
4101 -- System.Storage_Elements are not considered to be known.
4102 -- System.Auxxxx files are also considered known to the user.
4104 -- Should refine this at some point to generally distinguish
4105 -- between known and unknown internal files ???
4107 Get_Name_String (Fname);
4112 Name_Buffer (1 .. 2) /= "s-"
4114 Name_Buffer (3 .. 8) = "stoele"
4116 Name_Buffer (3 .. 5) = "aux";
4118 -- If not an internal file, then entity is definitely known,
4119 -- even if it is in a private part (the message generated will
4120 -- note that it is in a private part)
4125 end Known_But_Invisible;
4131 procedure Nvis_Messages is
4132 Comp_Unit : Node_Id;
4134 Found : Boolean := False;
4135 Hidden : Boolean := False;
4139 -- Ada 2005 (AI-262): Generate a precise error concerning the
4140 -- Beaujolais effect that was previously detected
4142 if Nvis_Is_Private_Subprg then
4144 pragma Assert (Nkind (E2) = N_Defining_Identifier
4145 and then Ekind (E2) = E_Function
4146 and then Scope (E2) = Standard_Standard
4147 and then Has_Private_With (E2));
4149 -- Find the sloc corresponding to the private with'ed unit
4151 Comp_Unit := Cunit (Current_Sem_Unit);
4152 Error_Msg_Sloc := No_Location;
4154 Item := First (Context_Items (Comp_Unit));
4155 while Present (Item) loop
4156 if Nkind (Item) = N_With_Clause
4157 and then Private_Present (Item)
4158 and then Entity (Name (Item)) = E2
4160 Error_Msg_Sloc := Sloc (Item);
4167 pragma Assert (Error_Msg_Sloc /= No_Location);
4169 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
4173 Undefined (Nvis => True);
4177 -- First loop does hidden declarations
4180 while Present (Ent) loop
4181 if Is_Potentially_Use_Visible (Ent) then
4183 Error_Msg_N -- CODEFIX
4184 ("multiple use clauses cause hiding!", N);
4188 Error_Msg_Sloc := Sloc (Ent);
4189 Error_Msg_N -- CODEFIX
4190 ("hidden declaration#!", N);
4193 Ent := Homonym (Ent);
4196 -- If we found hidden declarations, then that's enough, don't
4197 -- bother looking for non-visible declarations as well.
4203 -- Second loop does non-directly visible declarations
4206 while Present (Ent) loop
4207 if not Is_Potentially_Use_Visible (Ent) then
4209 -- Do not bother the user with unknown entities
4211 if not Known_But_Invisible (Ent) then
4215 Error_Msg_Sloc := Sloc (Ent);
4217 -- Output message noting that there is a non-visible
4218 -- declaration, distinguishing the private part case.
4220 if Is_Hidden (Ent) then
4221 Error_Msg_N ("non-visible (private) declaration#!", N);
4223 -- If the entity is declared in a generic package, it
4224 -- cannot be visible, so there is no point in adding it
4225 -- to the list of candidates if another homograph from a
4226 -- non-generic package has been seen.
4228 elsif Ekind (Scope (Ent)) = E_Generic_Package
4234 Error_Msg_N -- CODEFIX
4235 ("non-visible declaration#!", N);
4237 if Ekind (Scope (Ent)) /= E_Generic_Package then
4241 if Is_Compilation_Unit (Ent)
4243 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
4245 Error_Msg_Qual_Level := 99;
4246 Error_Msg_NE -- CODEFIX
4247 ("\\missing `WITH &;`", N, Ent);
4248 Error_Msg_Qual_Level := 0;
4251 if Ekind (Ent) = E_Discriminant
4252 and then Present (Corresponding_Discriminant (Ent))
4253 and then Scope (Corresponding_Discriminant (Ent)) =
4257 ("inherited discriminant not allowed here" &
4258 " (RM 3.8 (12), 3.8.1 (6))!", N);
4262 -- Set entity and its containing package as referenced. We
4263 -- can't be sure of this, but this seems a better choice
4264 -- to avoid unused entity messages.
4266 if Comes_From_Source (Ent) then
4267 Set_Referenced (Ent);
4268 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
4273 Ent := Homonym (Ent);
4282 procedure Undefined (Nvis : Boolean) is
4283 Emsg : Error_Msg_Id;
4286 -- We should never find an undefined internal name. If we do, then
4287 -- see if we have previous errors. If so, ignore on the grounds that
4288 -- it is probably a cascaded message (e.g. a block label from a badly
4289 -- formed block). If no previous errors, then we have a real internal
4290 -- error of some kind so raise an exception.
4292 if Is_Internal_Name (Chars (N)) then
4293 if Total_Errors_Detected /= 0 then
4296 raise Program_Error;
4300 -- A very specialized error check, if the undefined variable is
4301 -- a case tag, and the case type is an enumeration type, check
4302 -- for a possible misspelling, and if so, modify the identifier
4304 -- Named aggregate should also be handled similarly ???
4306 if Nkind (N) = N_Identifier
4307 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
4310 Case_Stm : constant Node_Id := Parent (Parent (N));
4311 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
4316 if Is_Enumeration_Type (Case_Typ)
4317 and then not Is_Standard_Character_Type (Case_Typ)
4319 Lit := First_Literal (Case_Typ);
4320 Get_Name_String (Chars (Lit));
4322 if Chars (Lit) /= Chars (N)
4323 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
4324 Error_Msg_Node_2 := Lit;
4325 Error_Msg_N -- CODEFIX
4326 ("& is undefined, assume misspelling of &", N);
4327 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
4331 Lit := Next_Literal (Lit);
4336 -- Normal processing
4338 Set_Entity (N, Any_Id);
4339 Set_Etype (N, Any_Type);
4341 -- We use the table Urefs to keep track of entities for which we
4342 -- have issued errors for undefined references. Multiple errors
4343 -- for a single name are normally suppressed, however we modify
4344 -- the error message to alert the programmer to this effect.
4346 for J in Urefs.First .. Urefs.Last loop
4347 if Chars (N) = Chars (Urefs.Table (J).Node) then
4348 if Urefs.Table (J).Err /= No_Error_Msg
4349 and then Sloc (N) /= Urefs.Table (J).Loc
4351 Error_Msg_Node_1 := Urefs.Table (J).Node;
4353 if Urefs.Table (J).Nvis then
4354 Change_Error_Text (Urefs.Table (J).Err,
4355 "& is not visible (more references follow)");
4357 Change_Error_Text (Urefs.Table (J).Err,
4358 "& is undefined (more references follow)");
4361 Urefs.Table (J).Err := No_Error_Msg;
4364 -- Although we will set Msg False, and thus suppress the
4365 -- message, we also set Error_Posted True, to avoid any
4366 -- cascaded messages resulting from the undefined reference.
4369 Set_Error_Posted (N, True);
4374 -- If entry not found, this is first undefined occurrence
4377 Error_Msg_N ("& is not visible!", N);
4381 Error_Msg_N ("& is undefined!", N);
4384 -- A very bizarre special check, if the undefined identifier
4385 -- is put or put_line, then add a special error message (since
4386 -- this is a very common error for beginners to make).
4388 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
4389 Error_Msg_N -- CODEFIX
4390 ("\\possible missing `WITH Ada.Text_'I'O; " &
4391 "USE Ada.Text_'I'O`!", N);
4393 -- Another special check if N is the prefix of a selected
4394 -- component which is a known unit, add message complaining
4395 -- about missing with for this unit.
4397 elsif Nkind (Parent (N)) = N_Selected_Component
4398 and then N = Prefix (Parent (N))
4399 and then Is_Known_Unit (Parent (N))
4401 Error_Msg_Node_2 := Selector_Name (Parent (N));
4402 Error_Msg_N -- CODEFIX
4403 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
4406 -- Now check for possible misspellings
4410 Ematch : Entity_Id := Empty;
4412 Last_Name_Id : constant Name_Id :=
4413 Name_Id (Nat (First_Name_Id) +
4414 Name_Entries_Count - 1);
4417 for Nam in First_Name_Id .. Last_Name_Id loop
4418 E := Get_Name_Entity_Id (Nam);
4421 and then (Is_Immediately_Visible (E)
4423 Is_Potentially_Use_Visible (E))
4425 if Is_Bad_Spelling_Of (Chars (N), Nam) then
4432 if Present (Ematch) then
4433 Error_Msg_NE -- CODEFIX
4434 ("\possible misspelling of&", N, Ematch);
4439 -- Make entry in undefined references table unless the full errors
4440 -- switch is set, in which case by refraining from generating the
4441 -- table entry, we guarantee that we get an error message for every
4442 -- undefined reference.
4444 if not All_Errors_Mode then
4455 -- Start of processing for Find_Direct_Name
4458 -- If the entity pointer is already set, this is an internal node, or
4459 -- a node that is analyzed more than once, after a tree modification.
4460 -- In such a case there is no resolution to perform, just set the type.
4462 if Present (Entity (N)) then
4463 if Is_Type (Entity (N)) then
4464 Set_Etype (N, Entity (N));
4468 Entyp : constant Entity_Id := Etype (Entity (N));
4471 -- One special case here. If the Etype field is already set,
4472 -- and references the packed array type corresponding to the
4473 -- etype of the referenced entity, then leave it alone. This
4474 -- happens for trees generated from Exp_Pakd, where expressions
4475 -- can be deliberately "mis-typed" to the packed array type.
4477 if Is_Array_Type (Entyp)
4478 and then Is_Packed (Entyp)
4479 and then Present (Etype (N))
4480 and then Etype (N) = Packed_Array_Type (Entyp)
4484 -- If not that special case, then just reset the Etype
4487 Set_Etype (N, Etype (Entity (N)));
4495 -- Here if Entity pointer was not set, we need full visibility analysis
4496 -- First we generate debugging output if the debug E flag is set.
4498 if Debug_Flag_E then
4499 Write_Str ("Looking for ");
4500 Write_Name (Chars (N));
4504 Homonyms := Current_Entity (N);
4505 Nvis_Entity := False;
4508 while Present (E) loop
4510 -- If entity is immediately visible or potentially use visible, then
4511 -- process the entity and we are done.
4513 if Is_Immediately_Visible (E) then
4514 goto Immediately_Visible_Entity;
4516 elsif Is_Potentially_Use_Visible (E) then
4517 goto Potentially_Use_Visible_Entity;
4519 -- Note if a known but invisible entity encountered
4521 elsif Known_But_Invisible (E) then
4522 Nvis_Entity := True;
4525 -- Move to next entity in chain and continue search
4530 -- If no entries on homonym chain that were potentially visible,
4531 -- and no entities reasonably considered as non-visible, then
4532 -- we have a plain undefined reference, with no additional
4533 -- explanation required!
4535 if not Nvis_Entity then
4536 Undefined (Nvis => False);
4538 -- Otherwise there is at least one entry on the homonym chain that
4539 -- is reasonably considered as being known and non-visible.
4547 -- Processing for a potentially use visible entry found. We must search
4548 -- the rest of the homonym chain for two reasons. First, if there is a
4549 -- directly visible entry, then none of the potentially use-visible
4550 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4551 -- for the case of multiple potentially use-visible entries hiding one
4552 -- another and as a result being non-directly visible (RM 8.4(11)).
4554 <<Potentially_Use_Visible_Entity>> declare
4555 Only_One_Visible : Boolean := True;
4556 All_Overloadable : Boolean := Is_Overloadable (E);
4560 while Present (E2) loop
4561 if Is_Immediately_Visible (E2) then
4563 -- If the use-visible entity comes from the actual for a
4564 -- formal package, it hides a directly visible entity from
4565 -- outside the instance.
4567 if From_Actual_Package (E)
4568 and then Scope_Depth (E2) < Scope_Depth (Inst)
4573 goto Immediately_Visible_Entity;
4576 elsif Is_Potentially_Use_Visible (E2) then
4577 Only_One_Visible := False;
4578 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4580 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4581 -- that can occur in private_with clauses. Example:
4584 -- private with B; package A is
4585 -- package C is function B return Integer;
4587 -- V1 : Integer := B;
4588 -- private function B return Integer;
4589 -- V2 : Integer := B;
4592 -- V1 resolves to A.B, but V2 resolves to library unit B
4594 elsif Ekind (E2) = E_Function
4595 and then Scope (E2) = Standard_Standard
4596 and then Has_Private_With (E2)
4598 Only_One_Visible := False;
4599 All_Overloadable := False;
4600 Nvis_Is_Private_Subprg := True;
4607 -- On falling through this loop, we have checked that there are no
4608 -- immediately visible entities. Only_One_Visible is set if exactly
4609 -- one potentially use visible entity exists. All_Overloadable is
4610 -- set if all the potentially use visible entities are overloadable.
4611 -- The condition for legality is that either there is one potentially
4612 -- use visible entity, or if there is more than one, then all of them
4613 -- are overloadable.
4615 if Only_One_Visible or All_Overloadable then
4618 -- If there is more than one potentially use-visible entity and at
4619 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4620 -- Note that E points to the first such entity on the homonym list.
4621 -- Special case: if one of the entities is declared in an actual
4622 -- package, it was visible in the generic, and takes precedence over
4623 -- other entities that are potentially use-visible. Same if it is
4624 -- declared in a local instantiation of the current instance.
4629 -- Find current instance
4631 Inst := Current_Scope;
4632 while Present (Inst)
4633 and then Inst /= Standard_Standard
4635 if Is_Generic_Instance (Inst) then
4639 Inst := Scope (Inst);
4643 while Present (E2) loop
4644 if From_Actual_Package (E2)
4646 (Is_Generic_Instance (Scope (E2))
4647 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4660 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4662 -- A use-clause in the body of a system file creates conflict
4663 -- with some entity in a user scope, while rtsfind is active.
4664 -- Keep only the entity coming from another predefined unit.
4667 while Present (E2) loop
4668 if Is_Predefined_File_Name
4669 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4678 -- Entity must exist because predefined unit is correct
4680 raise Program_Error;
4689 -- Come here with E set to the first immediately visible entity on
4690 -- the homonym chain. This is the one we want unless there is another
4691 -- immediately visible entity further on in the chain for an inner
4692 -- scope (RM 8.3(8)).
4694 <<Immediately_Visible_Entity>> declare
4699 -- Find scope level of initial entity. When compiling through
4700 -- Rtsfind, the previous context is not completely invisible, and
4701 -- an outer entity may appear on the chain, whose scope is below
4702 -- the entry for Standard that delimits the current scope stack.
4703 -- Indicate that the level for this spurious entry is outside of
4704 -- the current scope stack.
4706 Level := Scope_Stack.Last;
4708 Scop := Scope_Stack.Table (Level).Entity;
4709 exit when Scop = Scope (E);
4711 exit when Scop = Standard_Standard;
4714 -- Now search remainder of homonym chain for more inner entry
4715 -- If the entity is Standard itself, it has no scope, and we
4716 -- compare it with the stack entry directly.
4719 while Present (E2) loop
4720 if Is_Immediately_Visible (E2) then
4722 -- If a generic package contains a local declaration that
4723 -- has the same name as the generic, there may be a visibility
4724 -- conflict in an instance, where the local declaration must
4725 -- also hide the name of the corresponding package renaming.
4726 -- We check explicitly for a package declared by a renaming,
4727 -- whose renamed entity is an instance that is on the scope
4728 -- stack, and that contains a homonym in the same scope. Once
4729 -- we have found it, we know that the package renaming is not
4730 -- immediately visible, and that the identifier denotes the
4731 -- other entity (and its homonyms if overloaded).
4733 if Scope (E) = Scope (E2)
4734 and then Ekind (E) = E_Package
4735 and then Present (Renamed_Object (E))
4736 and then Is_Generic_Instance (Renamed_Object (E))
4737 and then In_Open_Scopes (Renamed_Object (E))
4738 and then Comes_From_Source (N)
4740 Set_Is_Immediately_Visible (E, False);
4744 for J in Level + 1 .. Scope_Stack.Last loop
4745 if Scope_Stack.Table (J).Entity = Scope (E2)
4746 or else Scope_Stack.Table (J).Entity = E2
4759 -- At the end of that loop, E is the innermost immediately
4760 -- visible entity, so we are all set.
4763 -- Come here with entity found, and stored in E
4767 -- Check violation of No_Wide_Characters restriction
4769 Check_Wide_Character_Restriction (E, N);
4771 -- When distribution features are available (Get_PCS_Name /=
4772 -- Name_No_DSA), a remote access-to-subprogram type is converted
4773 -- into a record type holding whatever information is needed to
4774 -- perform a remote call on an RCI subprogram. In that case we
4775 -- rewrite any occurrence of the RAS type into the equivalent record
4776 -- type here. 'Access attribute references and RAS dereferences are
4777 -- then implemented using specific TSSs. However when distribution is
4778 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4779 -- generation of these TSSs, and we must keep the RAS type in its
4780 -- original access-to-subprogram form (since all calls through a
4781 -- value of such type will be local anyway in the absence of a PCS).
4783 if Comes_From_Source (N)
4784 and then Is_Remote_Access_To_Subprogram_Type (E)
4785 and then Expander_Active
4786 and then Get_PCS_Name /= Name_No_DSA
4789 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4793 -- Set the entity. Note that the reason we call Set_Entity for the
4794 -- overloadable case, as opposed to Set_Entity_With_Style_Check is
4795 -- that in the overloaded case, the initial call can set the wrong
4796 -- homonym. The call that sets the right homonym is in Sem_Res and
4797 -- that call does use Set_Entity_With_Style_Check, so we don't miss
4800 if Is_Overloadable (E) then
4803 Set_Entity_With_Style_Check (N, E);
4809 Set_Etype (N, Get_Full_View (Etype (E)));
4812 if Debug_Flag_E then
4813 Write_Str (" found ");
4814 Write_Entity_Info (E, " ");
4817 -- If the Ekind of the entity is Void, it means that all homonyms
4818 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4819 -- test is skipped if the current scope is a record and the name is
4820 -- a pragma argument expression (case of Atomic and Volatile pragmas
4821 -- and possibly other similar pragmas added later, which are allowed
4822 -- to reference components in the current record).
4824 if Ekind (E) = E_Void
4826 (not Is_Record_Type (Current_Scope)
4827 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4829 Premature_Usage (N);
4831 -- If the entity is overloadable, collect all interpretations of the
4832 -- name for subsequent overload resolution. We optimize a bit here to
4833 -- do this only if we have an overloadable entity that is not on its
4834 -- own on the homonym chain.
4836 elsif Is_Overloadable (E)
4837 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4839 Collect_Interps (N);
4841 -- If no homonyms were visible, the entity is unambiguous
4843 if not Is_Overloaded (N) then
4844 if not Is_Actual_Parameter then
4845 Generate_Reference (E, N);
4849 -- Case of non-overloadable entity, set the entity providing that
4850 -- we do not have the case of a discriminant reference within a
4851 -- default expression. Such references are replaced with the
4852 -- corresponding discriminal, which is the formal corresponding to
4853 -- to the discriminant in the initialization procedure.
4856 -- Entity is unambiguous, indicate that it is referenced here
4858 -- For a renaming of an object, always generate simple reference,
4859 -- we don't try to keep track of assignments in this case.
4861 if Is_Object (E) and then Present (Renamed_Object (E)) then
4862 Generate_Reference (E, N);
4864 -- If the renamed entity is a private protected component,
4865 -- reference the original component as well. This needs to be
4866 -- done because the private renamings are installed before any
4867 -- analysis has occurred. Reference to a private component will
4868 -- resolve to the renaming and the original component will be
4869 -- left unreferenced, hence the following.
4871 if Is_Prival (E) then
4872 Generate_Reference (Prival_Link (E), N);
4875 -- One odd case is that we do not want to set the Referenced flag
4876 -- if the entity is a label, and the identifier is the label in
4877 -- the source, since this is not a reference from the point of
4878 -- view of the user.
4880 elsif Nkind (Parent (N)) = N_Label then
4882 R : constant Boolean := Referenced (E);
4885 -- Generate reference unless this is an actual parameter
4886 -- (see comment below)
4888 if Is_Actual_Parameter then
4889 Generate_Reference (E, N);
4890 Set_Referenced (E, R);
4894 -- Normal case, not a label: generate reference
4896 -- ??? It is too early to generate a reference here even if the
4897 -- entity is unambiguous, because the tree is not sufficiently
4898 -- typed at this point for Generate_Reference to determine
4899 -- whether this reference modifies the denoted object (because
4900 -- implicit dereferences cannot be identified prior to full type
4903 -- The Is_Actual_Parameter routine takes care of one of these
4904 -- cases but there are others probably ???
4906 -- If the entity is the LHS of an assignment, and is a variable
4907 -- (rather than a package prefix), we can mark it as a
4908 -- modification right away, to avoid duplicate references.
4911 if not Is_Actual_Parameter then
4913 and then Ekind (E) /= E_Package
4914 and then Ekind (E) /= E_Generic_Package
4916 Generate_Reference (E, N, 'm');
4918 Generate_Reference (E, N);
4922 Check_Nested_Access (E);
4925 Set_Entity_Or_Discriminal (N, E);
4927 if Ada_Version >= Ada_2012
4929 (Nkind (Parent (N)) in N_Subexpr
4930 or else Nkind (Parent (N)) = N_Object_Declaration)
4932 Check_Implicit_Dereference (N, Etype (E));
4936 end Find_Direct_Name;
4938 ------------------------
4939 -- Find_Expanded_Name --
4940 ------------------------
4942 -- This routine searches the homonym chain of the entity until it finds
4943 -- an entity declared in the scope denoted by the prefix. If the entity
4944 -- is private, it may nevertheless be immediately visible, if we are in
4945 -- the scope of its declaration.
4947 procedure Find_Expanded_Name (N : Node_Id) is
4948 Selector : constant Node_Id := Selector_Name (N);
4949 Candidate : Entity_Id := Empty;
4955 P_Name := Entity (Prefix (N));
4958 -- If the prefix is a renamed package, look for the entity in the
4959 -- original package.
4961 if Ekind (P_Name) = E_Package
4962 and then Present (Renamed_Object (P_Name))
4964 P_Name := Renamed_Object (P_Name);
4966 -- Rewrite node with entity field pointing to renamed object
4968 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4969 Set_Entity (Prefix (N), P_Name);
4971 -- If the prefix is an object of a concurrent type, look for
4972 -- the entity in the associated task or protected type.
4974 elsif Is_Concurrent_Type (Etype (P_Name)) then
4975 P_Name := Etype (P_Name);
4978 Id := Current_Entity (Selector);
4981 Is_New_Candidate : Boolean;
4984 while Present (Id) loop
4985 if Scope (Id) = P_Name then
4987 Is_New_Candidate := True;
4989 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4990 -- declared in limited-withed nested packages. We don't need to
4991 -- handle E_Incomplete_Subtype entities because the entities in
4992 -- the limited view are always E_Incomplete_Type entities (see
4993 -- Build_Limited_Views). Regarding the expression used to evaluate
4994 -- the scope, it is important to note that the limited view also
4995 -- has shadow entities associated nested packages. For this reason
4996 -- the correct scope of the entity is the scope of the real entity
4997 -- The non-limited view may itself be incomplete, in which case
4998 -- get the full view if available.
5000 elsif From_With_Type (Id)
5001 and then Is_Type (Id)
5002 and then Ekind (Id) = E_Incomplete_Type
5003 and then Present (Non_Limited_View (Id))
5004 and then Scope (Non_Limited_View (Id)) = P_Name
5006 Candidate := Get_Full_View (Non_Limited_View (Id));
5007 Is_New_Candidate := True;
5010 Is_New_Candidate := False;
5013 if Is_New_Candidate then
5014 if Is_Child_Unit (Id) then
5015 exit when Is_Visible_Child_Unit (Id)
5016 or else Is_Immediately_Visible (Id);
5019 exit when not Is_Hidden (Id)
5020 or else Is_Immediately_Visible (Id);
5029 and then (Ekind (P_Name) = E_Procedure
5031 Ekind (P_Name) = E_Function)
5032 and then Is_Generic_Instance (P_Name)
5034 -- Expanded name denotes entity in (instance of) generic subprogram.
5035 -- The entity may be in the subprogram instance, or may denote one of
5036 -- the formals, which is declared in the enclosing wrapper package.
5038 P_Name := Scope (P_Name);
5040 Id := Current_Entity (Selector);
5041 while Present (Id) loop
5042 exit when Scope (Id) = P_Name;
5047 if No (Id) or else Chars (Id) /= Chars (Selector) then
5048 Set_Etype (N, Any_Type);
5050 -- If we are looking for an entity defined in System, try to find it
5051 -- in the child package that may have been provided as an extension
5052 -- to System. The Extend_System pragma will have supplied the name of
5053 -- the extension, which may have to be loaded.
5055 if Chars (P_Name) = Name_System
5056 and then Scope (P_Name) = Standard_Standard
5057 and then Present (System_Extend_Unit)
5058 and then Present_System_Aux (N)
5060 Set_Entity (Prefix (N), System_Aux_Id);
5061 Find_Expanded_Name (N);
5064 elsif Nkind (Selector) = N_Operator_Symbol
5065 and then Has_Implicit_Operator (N)
5067 -- There is an implicit instance of the predefined operator in
5068 -- the given scope. The operator entity is defined in Standard.
5069 -- Has_Implicit_Operator makes the node into an Expanded_Name.
5073 elsif Nkind (Selector) = N_Character_Literal
5074 and then Has_Implicit_Character_Literal (N)
5076 -- If there is no literal defined in the scope denoted by the
5077 -- prefix, the literal may belong to (a type derived from)
5078 -- Standard_Character, for which we have no explicit literals.
5083 -- If the prefix is a single concurrent object, use its name in
5084 -- the error message, rather than that of the anonymous type.
5086 if Is_Concurrent_Type (P_Name)
5087 and then Is_Internal_Name (Chars (P_Name))
5089 Error_Msg_Node_2 := Entity (Prefix (N));
5091 Error_Msg_Node_2 := P_Name;
5094 if P_Name = System_Aux_Id then
5095 P_Name := Scope (P_Name);
5096 Set_Entity (Prefix (N), P_Name);
5099 if Present (Candidate) then
5101 -- If we know that the unit is a child unit we can give a more
5102 -- accurate error message.
5104 if Is_Child_Unit (Candidate) then
5106 -- If the candidate is a private child unit and we are in
5107 -- the visible part of a public unit, specialize the error
5108 -- message. There might be a private with_clause for it,
5109 -- but it is not currently active.
5111 if Is_Private_Descendant (Candidate)
5112 and then Ekind (Current_Scope) = E_Package
5113 and then not In_Private_Part (Current_Scope)
5114 and then not Is_Private_Descendant (Current_Scope)
5116 Error_Msg_N ("private child unit& is not visible here",
5119 -- Normal case where we have a missing with for a child unit
5122 Error_Msg_Qual_Level := 99;
5123 Error_Msg_NE -- CODEFIX
5124 ("missing `WITH &;`", Selector, Candidate);
5125 Error_Msg_Qual_Level := 0;
5128 -- Here we don't know that this is a child unit
5131 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
5135 -- Within the instantiation of a child unit, the prefix may
5136 -- denote the parent instance, but the selector has the name
5137 -- of the original child. Find whether we are within the
5138 -- corresponding instance, and get the proper entity, which
5139 -- can only be an enclosing scope.
5142 and then In_Open_Scopes (P_Name)
5143 and then Is_Generic_Instance (P_Name)
5146 S : Entity_Id := Current_Scope;
5150 for J in reverse 0 .. Scope_Stack.Last loop
5151 S := Scope_Stack.Table (J).Entity;
5153 exit when S = Standard_Standard;
5155 if Ekind_In (S, E_Function,
5159 P := Generic_Parent (Specification
5160 (Unit_Declaration_Node (S)));
5163 and then Chars (Scope (P)) = Chars (O_Name)
5164 and then Chars (P) = Chars (Selector)
5175 -- If this is a selection from Ada, System or Interfaces, then
5176 -- we assume a missing with for the corresponding package.
5178 if Is_Known_Unit (N) then
5179 if not Error_Posted (N) then
5180 Error_Msg_Node_2 := Selector;
5181 Error_Msg_N -- CODEFIX
5182 ("missing `WITH &.&;`", Prefix (N));
5185 -- If this is a selection from a dummy package, then suppress
5186 -- the error message, of course the entity is missing if the
5187 -- package is missing!
5189 elsif Sloc (Error_Msg_Node_2) = No_Location then
5192 -- Here we have the case of an undefined component
5196 -- The prefix may hide a homonym in the context that
5197 -- declares the desired entity. This error can use a
5198 -- specialized message.
5200 if In_Open_Scopes (P_Name)
5201 and then Present (Homonym (P_Name))
5202 and then Is_Compilation_Unit (Homonym (P_Name))
5204 (Is_Immediately_Visible (Homonym (P_Name))
5205 or else Is_Visible_Child_Unit (Homonym (P_Name)))
5208 H : constant Entity_Id := Homonym (P_Name);
5211 Id := First_Entity (H);
5212 while Present (Id) loop
5213 if Chars (Id) = Chars (Selector) then
5214 Error_Msg_Qual_Level := 99;
5215 Error_Msg_Name_1 := Chars (Selector);
5217 ("% not declared in&", N, P_Name);
5219 ("\use fully qualified name starting with"
5220 & " Standard to make& visible", N, H);
5221 Error_Msg_Qual_Level := 0;
5228 -- If not found, standard error message
5230 Error_Msg_NE ("& not declared in&", N, Selector);
5236 Error_Msg_NE ("& not declared in&", N, Selector);
5239 -- Check for misspelling of some entity in prefix
5241 Id := First_Entity (P_Name);
5242 while Present (Id) loop
5243 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
5244 and then not Is_Internal_Name (Chars (Id))
5246 Error_Msg_NE -- CODEFIX
5247 ("possible misspelling of&", Selector, Id);
5254 -- Specialize the message if this may be an instantiation
5255 -- of a child unit that was not mentioned in the context.
5257 if Nkind (Parent (N)) = N_Package_Instantiation
5258 and then Is_Generic_Instance (Entity (Prefix (N)))
5259 and then Is_Compilation_Unit
5260 (Generic_Parent (Parent (Entity (Prefix (N)))))
5262 Error_Msg_Node_2 := Selector;
5263 Error_Msg_N -- CODEFIX
5264 ("\missing `WITH &.&;`", Prefix (N));
5274 if Comes_From_Source (N)
5275 and then Is_Remote_Access_To_Subprogram_Type (Id)
5276 and then Present (Equivalent_Type (Id))
5278 -- If we are not actually generating distribution code (i.e. the
5279 -- current PCS is the dummy non-distributed version), then the
5280 -- Equivalent_Type will be missing, and Id should be treated as
5281 -- a regular access-to-subprogram type.
5283 Id := Equivalent_Type (Id);
5284 Set_Chars (Selector, Chars (Id));
5287 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
5289 if Ekind (P_Name) = E_Package
5290 and then From_With_Type (P_Name)
5292 if From_With_Type (Id)
5293 or else Is_Type (Id)
5294 or else Ekind (Id) = E_Package
5299 ("limited withed package can only be used to access "
5300 & "incomplete types",
5305 if Is_Task_Type (P_Name)
5306 and then ((Ekind (Id) = E_Entry
5307 and then Nkind (Parent (N)) /= N_Attribute_Reference)
5309 (Ekind (Id) = E_Entry_Family
5311 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
5313 -- It is an entry call after all, either to the current task (which
5314 -- will deadlock) or to an enclosing task.
5316 Analyze_Selected_Component (N);
5320 Change_Selected_Component_To_Expanded_Name (N);
5322 -- Do style check and generate reference, but skip both steps if this
5323 -- entity has homonyms, since we may not have the right homonym set yet.
5324 -- The proper homonym will be set during the resolve phase.
5326 if Has_Homonym (Id) then
5329 Set_Entity_Or_Discriminal (N, Id);
5332 Generate_Reference (Id, N, 'm');
5334 Generate_Reference (Id, N);
5338 if Is_Type (Id) then
5341 Set_Etype (N, Get_Full_View (Etype (Id)));
5344 -- Check for violation of No_Wide_Characters
5346 Check_Wide_Character_Restriction (Id, N);
5348 -- If the Ekind of the entity is Void, it means that all homonyms are
5349 -- hidden from all visibility (RM 8.3(5,14-20)).
5351 if Ekind (Id) = E_Void then
5352 Premature_Usage (N);
5354 elsif Is_Overloadable (Id)
5355 and then Present (Homonym (Id))
5358 H : Entity_Id := Homonym (Id);
5361 while Present (H) loop
5362 if Scope (H) = Scope (Id)
5365 or else Is_Immediately_Visible (H))
5367 Collect_Interps (N);
5374 -- If an extension of System is present, collect possible explicit
5375 -- overloadings declared in the extension.
5377 if Chars (P_Name) = Name_System
5378 and then Scope (P_Name) = Standard_Standard
5379 and then Present (System_Extend_Unit)
5380 and then Present_System_Aux (N)
5382 H := Current_Entity (Id);
5384 while Present (H) loop
5385 if Scope (H) = System_Aux_Id then
5386 Add_One_Interp (N, H, Etype (H));
5395 if Nkind (Selector_Name (N)) = N_Operator_Symbol
5396 and then Scope (Id) /= Standard_Standard
5398 -- In addition to user-defined operators in the given scope, there
5399 -- may be an implicit instance of the predefined operator. The
5400 -- operator (defined in Standard) is found in Has_Implicit_Operator,
5401 -- and added to the interpretations. Procedure Add_One_Interp will
5402 -- determine which hides which.
5404 if Has_Implicit_Operator (N) then
5408 end Find_Expanded_Name;
5410 -------------------------
5411 -- Find_Renamed_Entity --
5412 -------------------------
5414 function Find_Renamed_Entity
5418 Is_Actual : Boolean := False) return Entity_Id
5421 I1 : Interp_Index := 0; -- Suppress junk warnings
5427 function Enclosing_Instance return Entity_Id;
5428 -- If the renaming determines the entity for the default of a formal
5429 -- subprogram nested within another instance, choose the innermost
5430 -- candidate. This is because if the formal has a box, and we are within
5431 -- an enclosing instance where some candidate interpretations are local
5432 -- to this enclosing instance, we know that the default was properly
5433 -- resolved when analyzing the generic, so we prefer the local
5434 -- candidates to those that are external. This is not always the case
5435 -- but is a reasonable heuristic on the use of nested generics. The
5436 -- proper solution requires a full renaming model.
5438 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
5439 -- If the renamed entity is an implicit operator, check whether it is
5440 -- visible because its operand type is properly visible. This check
5441 -- applies to explicit renamed entities that appear in the source in a
5442 -- renaming declaration or a formal subprogram instance, but not to
5443 -- default generic actuals with a name.
5445 function Report_Overload return Entity_Id;
5446 -- List possible interpretations, and specialize message in the
5447 -- case of a generic actual.
5449 function Within (Inner, Outer : Entity_Id) return Boolean;
5450 -- Determine whether a candidate subprogram is defined within the
5451 -- enclosing instance. If yes, it has precedence over outer candidates.
5453 ------------------------
5454 -- Enclosing_Instance --
5455 ------------------------
5457 function Enclosing_Instance return Entity_Id is
5461 if not Is_Generic_Instance (Current_Scope)
5462 and then not Is_Actual
5467 S := Scope (Current_Scope);
5468 while S /= Standard_Standard loop
5469 if Is_Generic_Instance (S) then
5477 end Enclosing_Instance;
5479 --------------------------
5480 -- Is_Visible_Operation --
5481 --------------------------
5483 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
5489 if Ekind (Op) /= E_Operator
5490 or else Scope (Op) /= Standard_Standard
5491 or else (In_Instance
5494 or else Present (Enclosing_Instance)))
5499 -- For a fixed point type operator, check the resulting type,
5500 -- because it may be a mixed mode integer * fixed operation.
5502 if Present (Next_Formal (First_Formal (New_S)))
5503 and then Is_Fixed_Point_Type (Etype (New_S))
5505 Typ := Etype (New_S);
5507 Typ := Etype (First_Formal (New_S));
5510 Btyp := Base_Type (Typ);
5512 if Nkind (Nam) /= N_Expanded_Name then
5513 return (In_Open_Scopes (Scope (Btyp))
5514 or else Is_Potentially_Use_Visible (Btyp)
5515 or else In_Use (Btyp)
5516 or else In_Use (Scope (Btyp)));
5519 Scop := Entity (Prefix (Nam));
5521 if Ekind (Scop) = E_Package
5522 and then Present (Renamed_Object (Scop))
5524 Scop := Renamed_Object (Scop);
5527 -- Operator is visible if prefix of expanded name denotes
5528 -- scope of type, or else type is defined in System_Aux
5529 -- and the prefix denotes System.
5531 return Scope (Btyp) = Scop
5532 or else (Scope (Btyp) = System_Aux_Id
5533 and then Scope (Scope (Btyp)) = Scop);
5536 end Is_Visible_Operation;
5542 function Within (Inner, Outer : Entity_Id) return Boolean is
5546 Sc := Scope (Inner);
5547 while Sc /= Standard_Standard loop
5558 ---------------------
5559 -- Report_Overload --
5560 ---------------------
5562 function Report_Overload return Entity_Id is
5565 Error_Msg_NE -- CODEFIX
5566 ("ambiguous actual subprogram&, " &
5567 "possible interpretations:", N, Nam);
5569 Error_Msg_N -- CODEFIX
5570 ("ambiguous subprogram, " &
5571 "possible interpretations:", N);
5574 List_Interps (Nam, N);
5576 end Report_Overload;
5578 -- Start of processing for Find_Renamed_Entity
5582 Candidate_Renaming := Empty;
5584 if not Is_Overloaded (Nam) then
5585 if Entity_Matches_Spec (Entity (Nam), New_S) then
5586 Candidate_Renaming := New_S;
5588 if Is_Visible_Operation (Entity (Nam)) then
5589 Old_S := Entity (Nam);
5593 Present (First_Formal (Entity (Nam)))
5594 and then Present (First_Formal (New_S))
5595 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5596 = Base_Type (Etype (First_Formal (New_S))))
5598 Candidate_Renaming := Entity (Nam);
5602 Get_First_Interp (Nam, Ind, It);
5603 while Present (It.Nam) loop
5604 if Entity_Matches_Spec (It.Nam, New_S)
5605 and then Is_Visible_Operation (It.Nam)
5607 if Old_S /= Any_Id then
5609 -- Note: The call to Disambiguate only happens if a
5610 -- previous interpretation was found, in which case I1
5611 -- has received a value.
5613 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5615 if It1 = No_Interp then
5616 Inst := Enclosing_Instance;
5618 if Present (Inst) then
5619 if Within (It.Nam, Inst) then
5620 if Within (Old_S, Inst) then
5622 -- Choose the innermost subprogram, which would
5623 -- have hidden the outer one in the generic.
5625 if Scope_Depth (It.Nam) <
5634 elsif Within (Old_S, Inst) then
5638 return Report_Overload;
5641 -- If not within an instance, ambiguity is real
5644 return Report_Overload;
5658 Present (First_Formal (It.Nam))
5659 and then Present (First_Formal (New_S))
5660 and then (Base_Type (Etype (First_Formal (It.Nam)))
5661 = Base_Type (Etype (First_Formal (New_S))))
5663 Candidate_Renaming := It.Nam;
5666 Get_Next_Interp (Ind, It);
5669 Set_Entity (Nam, Old_S);
5671 if Old_S /= Any_Id then
5672 Set_Is_Overloaded (Nam, False);
5677 end Find_Renamed_Entity;
5679 -----------------------------
5680 -- Find_Selected_Component --
5681 -----------------------------
5683 procedure Find_Selected_Component (N : Node_Id) is
5684 P : constant Node_Id := Prefix (N);
5687 -- Entity denoted by prefix
5697 if Nkind (P) = N_Error then
5701 -- Selector name cannot be a character literal or an operator symbol in
5702 -- SPARK, except for the operator symbol in a renaming.
5704 if Restriction_Check_Required (SPARK) then
5705 if Nkind (Selector_Name (N)) = N_Character_Literal then
5706 Check_SPARK_Restriction
5707 ("character literal cannot be prefixed", N);
5708 elsif Nkind (Selector_Name (N)) = N_Operator_Symbol
5709 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
5711 Check_SPARK_Restriction ("operator symbol cannot be prefixed", N);
5715 -- If the selector already has an entity, the node has been constructed
5716 -- in the course of expansion, and is known to be valid. Do not verify
5717 -- that it is defined for the type (it may be a private component used
5718 -- in the expansion of record equality).
5720 if Present (Entity (Selector_Name (N))) then
5722 or else Etype (N) = Any_Type
5725 Sel_Name : constant Node_Id := Selector_Name (N);
5726 Selector : constant Entity_Id := Entity (Sel_Name);
5730 Set_Etype (Sel_Name, Etype (Selector));
5732 if not Is_Entity_Name (P) then
5736 -- Build an actual subtype except for the first parameter
5737 -- of an init proc, where this actual subtype is by
5738 -- definition incorrect, since the object is uninitialized
5739 -- (and does not even have defined discriminants etc.)
5741 if Is_Entity_Name (P)
5742 and then Ekind (Entity (P)) = E_Function
5744 Nam := New_Copy (P);
5746 if Is_Overloaded (P) then
5747 Save_Interps (P, Nam);
5751 Make_Function_Call (Sloc (P), Name => Nam));
5753 Analyze_Selected_Component (N);
5756 elsif Ekind (Selector) = E_Component
5757 and then (not Is_Entity_Name (P)
5758 or else Chars (Entity (P)) /= Name_uInit)
5760 -- Do not build the subtype when referencing components of
5761 -- dispatch table wrappers. Required to avoid generating
5762 -- elaboration code with HI runtimes. JVM and .NET use a
5763 -- modified version of Ada.Tags which does not contain RE_
5764 -- Dispatch_Table_Wrapper and RE_No_Dispatch_Table_Wrapper.
5765 -- Avoid raising RE_Not_Available exception in those cases.
5767 if VM_Target = No_VM
5768 and then RTU_Loaded (Ada_Tags)
5770 ((RTE_Available (RE_Dispatch_Table_Wrapper)
5771 and then Scope (Selector) =
5772 RTE (RE_Dispatch_Table_Wrapper))
5774 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
5775 and then Scope (Selector) =
5776 RTE (RE_No_Dispatch_Table_Wrapper)))
5782 Build_Actual_Subtype_Of_Component
5783 (Etype (Selector), N);
5790 if No (C_Etype) then
5791 C_Etype := Etype (Selector);
5793 Insert_Action (N, C_Etype);
5794 C_Etype := Defining_Identifier (C_Etype);
5797 Set_Etype (N, C_Etype);
5800 -- If this is the name of an entry or protected operation, and
5801 -- the prefix is an access type, insert an explicit dereference,
5802 -- so that entry calls are treated uniformly.
5804 if Is_Access_Type (Etype (P))
5805 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5808 New_P : constant Node_Id :=
5809 Make_Explicit_Dereference (Sloc (P),
5810 Prefix => Relocate_Node (P));
5813 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5817 -- If the selected component appears within a default expression
5818 -- and it has an actual subtype, the pre-analysis has not yet
5819 -- completed its analysis, because Insert_Actions is disabled in
5820 -- that context. Within the init proc of the enclosing type we
5821 -- must complete this analysis, if an actual subtype was created.
5823 elsif Inside_Init_Proc then
5825 Typ : constant Entity_Id := Etype (N);
5826 Decl : constant Node_Id := Declaration_Node (Typ);
5828 if Nkind (Decl) = N_Subtype_Declaration
5829 and then not Analyzed (Decl)
5830 and then Is_List_Member (Decl)
5831 and then No (Parent (Decl))
5834 Insert_Action (N, Decl);
5841 elsif Is_Entity_Name (P) then
5842 P_Name := Entity (P);
5844 -- The prefix may denote an enclosing type which is the completion
5845 -- of an incomplete type declaration.
5847 if Is_Type (P_Name) then
5848 Set_Entity (P, Get_Full_View (P_Name));
5849 Set_Etype (P, Entity (P));
5850 P_Name := Entity (P);
5853 P_Type := Base_Type (Etype (P));
5855 if Debug_Flag_E then
5856 Write_Str ("Found prefix type to be ");
5857 Write_Entity_Info (P_Type, " "); Write_Eol;
5860 -- First check for components of a record object (not the
5861 -- result of a call, which is handled below).
5863 if Is_Appropriate_For_Record (P_Type)
5864 and then not Is_Overloadable (P_Name)
5865 and then not Is_Type (P_Name)
5867 -- Selected component of record. Type checking will validate
5868 -- name of selector.
5869 -- ??? could we rewrite an implicit dereference into an explicit
5872 Analyze_Selected_Component (N);
5874 -- Reference to type name in predicate/invariant expression
5876 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5877 and then not In_Open_Scopes (P_Name)
5878 and then (not Is_Concurrent_Type (Etype (P_Name))
5879 or else not In_Open_Scopes (Etype (P_Name)))
5881 -- Call to protected operation or entry. Type checking is
5882 -- needed on the prefix.
5884 Analyze_Selected_Component (N);
5886 elsif (In_Open_Scopes (P_Name)
5887 and then Ekind (P_Name) /= E_Void
5888 and then not Is_Overloadable (P_Name))
5889 or else (Is_Concurrent_Type (Etype (P_Name))
5890 and then In_Open_Scopes (Etype (P_Name)))
5892 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5893 -- enclosing construct that is not a subprogram or accept.
5895 Find_Expanded_Name (N);
5897 elsif Ekind (P_Name) = E_Package then
5898 Find_Expanded_Name (N);
5900 elsif Is_Overloadable (P_Name) then
5902 -- The subprogram may be a renaming (of an enclosing scope) as
5903 -- in the case of the name of the generic within an instantiation.
5905 if Ekind_In (P_Name, E_Procedure, E_Function)
5906 and then Present (Alias (P_Name))
5907 and then Is_Generic_Instance (Alias (P_Name))
5909 P_Name := Alias (P_Name);
5912 if Is_Overloaded (P) then
5914 -- The prefix must resolve to a unique enclosing construct
5917 Found : Boolean := False;
5922 Get_First_Interp (P, Ind, It);
5923 while Present (It.Nam) loop
5924 if In_Open_Scopes (It.Nam) then
5927 "prefix must be unique enclosing scope", N);
5928 Set_Entity (N, Any_Id);
5929 Set_Etype (N, Any_Type);
5938 Get_Next_Interp (Ind, It);
5943 if In_Open_Scopes (P_Name) then
5944 Set_Entity (P, P_Name);
5945 Set_Is_Overloaded (P, False);
5946 Find_Expanded_Name (N);
5949 -- If no interpretation as an expanded name is possible, it
5950 -- must be a selected component of a record returned by a
5951 -- function call. Reformat prefix as a function call, the rest
5952 -- is done by type resolution. If the prefix is procedure or
5953 -- entry, as is P.X; this is an error.
5955 if Ekind (P_Name) /= E_Function
5956 and then (not Is_Overloaded (P)
5958 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5960 -- Prefix may mention a package that is hidden by a local
5961 -- declaration: let the user know. Scan the full homonym
5962 -- chain, the candidate package may be anywhere on it.
5964 if Present (Homonym (Current_Entity (P_Name))) then
5966 P_Name := Current_Entity (P_Name);
5968 while Present (P_Name) loop
5969 exit when Ekind (P_Name) = E_Package;
5970 P_Name := Homonym (P_Name);
5973 if Present (P_Name) then
5974 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5977 ("package& is hidden by declaration#",
5980 Set_Entity (Prefix (N), P_Name);
5981 Find_Expanded_Name (N);
5984 P_Name := Entity (Prefix (N));
5989 ("invalid prefix in selected component&", N, P_Name);
5990 Change_Selected_Component_To_Expanded_Name (N);
5991 Set_Entity (N, Any_Id);
5992 Set_Etype (N, Any_Type);
5995 Nam := New_Copy (P);
5996 Save_Interps (P, Nam);
5998 Make_Function_Call (Sloc (P), Name => Nam));
6000 Analyze_Selected_Component (N);
6004 -- Remaining cases generate various error messages
6007 -- Format node as expanded name, to avoid cascaded errors
6009 Change_Selected_Component_To_Expanded_Name (N);
6010 Set_Entity (N, Any_Id);
6011 Set_Etype (N, Any_Type);
6013 -- Issue error message, but avoid this if error issued already.
6014 -- Use identifier of prefix if one is available.
6016 if P_Name = Any_Id then
6019 elsif Ekind (P_Name) = E_Void then
6020 Premature_Usage (P);
6022 elsif Nkind (P) /= N_Attribute_Reference then
6024 "invalid prefix in selected component&", P);
6026 if Is_Access_Type (P_Type)
6027 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
6030 ("\dereference must not be of an incomplete type " &
6036 "invalid prefix in selected component", P);
6040 -- Selector name is restricted in SPARK
6042 if Nkind (N) = N_Expanded_Name
6043 and then Restriction_Check_Required (SPARK)
6045 if Is_Subprogram (P_Name) then
6046 Check_SPARK_Restriction
6047 ("prefix of expanded name cannot be a subprogram", P);
6048 elsif Ekind (P_Name) = E_Loop then
6049 Check_SPARK_Restriction
6050 ("prefix of expanded name cannot be a loop statement", P);
6055 -- If prefix is not the name of an entity, it must be an expression,
6056 -- whose type is appropriate for a record. This is determined by
6059 Analyze_Selected_Component (N);
6061 end Find_Selected_Component;
6067 procedure Find_Type (N : Node_Id) is
6077 elsif Nkind (N) = N_Attribute_Reference then
6079 -- Class attribute. This is not valid in Ada 83 mode, but we do not
6080 -- need to enforce that at this point, since the declaration of the
6081 -- tagged type in the prefix would have been flagged already.
6083 if Attribute_Name (N) = Name_Class then
6084 Check_Restriction (No_Dispatch, N);
6085 Find_Type (Prefix (N));
6087 -- Propagate error from bad prefix
6089 if Etype (Prefix (N)) = Any_Type then
6090 Set_Entity (N, Any_Type);
6091 Set_Etype (N, Any_Type);
6095 T := Base_Type (Entity (Prefix (N)));
6097 -- Case where type is not known to be tagged. Its appearance in
6098 -- the prefix of the 'Class attribute indicates that the full view
6101 if not Is_Tagged_Type (T) then
6102 if Ekind (T) = E_Incomplete_Type then
6104 -- It is legal to denote the class type of an incomplete
6105 -- type. The full type will have to be tagged, of course.
6106 -- In Ada 2005 this usage is declared obsolescent, so we
6107 -- warn accordingly. This usage is only legal if the type
6108 -- is completed in the current scope, and not for a limited
6111 if not Is_Tagged_Type (T)
6112 and then Ada_Version >= Ada_2005
6114 if From_With_Type (T) then
6116 ("prefix of Class attribute must be tagged", N);
6117 Set_Etype (N, Any_Type);
6118 Set_Entity (N, Any_Type);
6121 -- ??? This test is temporarily disabled (always False)
6122 -- because it causes an unwanted warning on GNAT sources
6123 -- (built with -gnatg, which includes Warn_On_Obsolescent_
6124 -- Feature). Once this issue is cleared in the sources, it
6127 elsif Warn_On_Obsolescent_Feature
6131 ("applying 'Class to an untagged incomplete type"
6132 & " is an obsolescent feature (RM J.11)", N);
6136 Set_Is_Tagged_Type (T);
6137 Set_Direct_Primitive_Operations (T, New_Elmt_List);
6138 Make_Class_Wide_Type (T);
6139 Set_Entity (N, Class_Wide_Type (T));
6140 Set_Etype (N, Class_Wide_Type (T));
6142 elsif Ekind (T) = E_Private_Type
6143 and then not Is_Generic_Type (T)
6144 and then In_Private_Part (Scope (T))
6146 -- The Class attribute can be applied to an untagged private
6147 -- type fulfilled by a tagged type prior to the full type
6148 -- declaration (but only within the parent package's private
6149 -- part). Create the class-wide type now and check that the
6150 -- full type is tagged later during its analysis. Note that
6151 -- we do not mark the private type as tagged, unlike the
6152 -- case of incomplete types, because the type must still
6153 -- appear untagged to outside units.
6155 if No (Class_Wide_Type (T)) then
6156 Make_Class_Wide_Type (T);
6159 Set_Entity (N, Class_Wide_Type (T));
6160 Set_Etype (N, Class_Wide_Type (T));
6163 -- Should we introduce a type Any_Tagged and use Wrong_Type
6164 -- here, it would be a bit more consistent???
6167 ("tagged type required, found}",
6168 Prefix (N), First_Subtype (T));
6169 Set_Entity (N, Any_Type);
6173 -- Case of tagged type
6176 if Is_Concurrent_Type (T) then
6177 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
6179 -- Previous error. Use current type, which at least
6180 -- provides some operations.
6182 C := Entity (Prefix (N));
6185 C := Class_Wide_Type
6186 (Corresponding_Record_Type (Entity (Prefix (N))));
6190 C := Class_Wide_Type (Entity (Prefix (N)));
6193 Set_Entity_With_Style_Check (N, C);
6194 Generate_Reference (C, N);
6198 -- Base attribute, not allowed in Ada 83
6200 elsif Attribute_Name (N) = Name_Base then
6201 Error_Msg_Name_1 := Name_Base;
6202 Check_SPARK_Restriction
6203 ("attribute% is only allowed as prefix of another attribute", N);
6205 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
6207 ("(Ada 83) Base attribute not allowed in subtype mark", N);
6210 Find_Type (Prefix (N));
6211 Typ := Entity (Prefix (N));
6213 if Ada_Version >= Ada_95
6214 and then not Is_Scalar_Type (Typ)
6215 and then not Is_Generic_Type (Typ)
6218 ("prefix of Base attribute must be scalar type",
6221 elsif Warn_On_Redundant_Constructs
6222 and then Base_Type (Typ) = Typ
6224 Error_Msg_NE -- CODEFIX
6225 ("?redundant attribute, & is its own base type", N, Typ);
6228 T := Base_Type (Typ);
6230 -- Rewrite attribute reference with type itself (see similar
6231 -- processing in Analyze_Attribute, case Base). Preserve prefix
6232 -- if present, for other legality checks.
6234 if Nkind (Prefix (N)) = N_Expanded_Name then
6236 Make_Expanded_Name (Sloc (N),
6238 Prefix => New_Copy (Prefix (Prefix (N))),
6239 Selector_Name => New_Reference_To (T, Sloc (N))));
6242 Rewrite (N, New_Reference_To (T, Sloc (N)));
6249 elsif Attribute_Name (N) = Name_Stub_Type then
6251 -- This is handled in Analyze_Attribute
6255 -- All other attributes are invalid in a subtype mark
6258 Error_Msg_N ("invalid attribute in subtype mark", N);
6264 if Is_Entity_Name (N) then
6265 T_Name := Entity (N);
6267 Error_Msg_N ("subtype mark required in this context", N);
6268 Set_Etype (N, Any_Type);
6272 if T_Name = Any_Id or else Etype (N) = Any_Type then
6274 -- Undefined id. Make it into a valid type
6276 Set_Entity (N, Any_Type);
6278 elsif not Is_Type (T_Name)
6279 and then T_Name /= Standard_Void_Type
6281 Error_Msg_Sloc := Sloc (T_Name);
6282 Error_Msg_N ("subtype mark required in this context", N);
6283 Error_Msg_NE ("\\found & declared#", N, T_Name);
6284 Set_Entity (N, Any_Type);
6287 -- If the type is an incomplete type created to handle
6288 -- anonymous access components of a record type, then the
6289 -- incomplete type is the visible entity and subsequent
6290 -- references will point to it. Mark the original full
6291 -- type as referenced, to prevent spurious warnings.
6293 if Is_Incomplete_Type (T_Name)
6294 and then Present (Full_View (T_Name))
6295 and then not Comes_From_Source (T_Name)
6297 Set_Referenced (Full_View (T_Name));
6300 T_Name := Get_Full_View (T_Name);
6302 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
6303 -- limited-with clauses
6305 if From_With_Type (T_Name)
6306 and then Ekind (T_Name) in Incomplete_Kind
6307 and then Present (Non_Limited_View (T_Name))
6308 and then Is_Interface (Non_Limited_View (T_Name))
6310 T_Name := Non_Limited_View (T_Name);
6313 if In_Open_Scopes (T_Name) then
6314 if Ekind (Base_Type (T_Name)) = E_Task_Type then
6316 -- In Ada 2005, a task name can be used in an access
6317 -- definition within its own body. It cannot be used
6318 -- in the discriminant part of the task declaration,
6319 -- nor anywhere else in the declaration because entries
6320 -- cannot have access parameters.
6322 if Ada_Version >= Ada_2005
6323 and then Nkind (Parent (N)) = N_Access_Definition
6325 Set_Entity (N, T_Name);
6326 Set_Etype (N, T_Name);
6328 if Has_Completion (T_Name) then
6333 ("task type cannot be used as type mark " &
6334 "within its own declaration", N);
6339 ("task type cannot be used as type mark " &
6340 "within its own spec or body", N);
6343 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
6345 -- In Ada 2005, a protected name can be used in an access
6346 -- definition within its own body.
6348 if Ada_Version >= Ada_2005
6349 and then Nkind (Parent (N)) = N_Access_Definition
6351 Set_Entity (N, T_Name);
6352 Set_Etype (N, T_Name);
6357 ("protected type cannot be used as type mark " &
6358 "within its own spec or body", N);
6362 Error_Msg_N ("type declaration cannot refer to itself", N);
6365 Set_Etype (N, Any_Type);
6366 Set_Entity (N, Any_Type);
6367 Set_Error_Posted (T_Name);
6371 Set_Entity (N, T_Name);
6372 Set_Etype (N, T_Name);
6376 if Present (Etype (N)) and then Comes_From_Source (N) then
6377 if Is_Fixed_Point_Type (Etype (N)) then
6378 Check_Restriction (No_Fixed_Point, N);
6379 elsif Is_Floating_Point_Type (Etype (N)) then
6380 Check_Restriction (No_Floating_Point, N);
6385 ------------------------------------
6386 -- Has_Implicit_Character_Literal --
6387 ------------------------------------
6389 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
6391 Found : Boolean := False;
6392 P : constant Entity_Id := Entity (Prefix (N));
6393 Priv_Id : Entity_Id := Empty;
6396 if Ekind (P) = E_Package
6397 and then not In_Open_Scopes (P)
6399 Priv_Id := First_Private_Entity (P);
6402 if P = Standard_Standard then
6403 Change_Selected_Component_To_Expanded_Name (N);
6404 Rewrite (N, Selector_Name (N));
6406 Set_Etype (Original_Node (N), Standard_Character);
6410 Id := First_Entity (P);
6412 and then Id /= Priv_Id
6414 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
6416 -- We replace the node with the literal itself, resolve as a
6417 -- character, and set the type correctly.
6420 Change_Selected_Component_To_Expanded_Name (N);
6421 Rewrite (N, Selector_Name (N));
6424 Set_Etype (Original_Node (N), Id);
6428 -- More than one type derived from Character in given scope.
6429 -- Collect all possible interpretations.
6431 Add_One_Interp (N, Id, Id);
6439 end Has_Implicit_Character_Literal;
6441 ----------------------
6442 -- Has_Private_With --
6443 ----------------------
6445 function Has_Private_With (E : Entity_Id) return Boolean is
6446 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
6450 Item := First (Context_Items (Comp_Unit));
6451 while Present (Item) loop
6452 if Nkind (Item) = N_With_Clause
6453 and then Private_Present (Item)
6454 and then Entity (Name (Item)) = E
6463 end Has_Private_With;
6465 ---------------------------
6466 -- Has_Implicit_Operator --
6467 ---------------------------
6469 function Has_Implicit_Operator (N : Node_Id) return Boolean is
6470 Op_Id : constant Name_Id := Chars (Selector_Name (N));
6471 P : constant Entity_Id := Entity (Prefix (N));
6473 Priv_Id : Entity_Id := Empty;
6475 procedure Add_Implicit_Operator
6477 Op_Type : Entity_Id := Empty);
6478 -- Add implicit interpretation to node N, using the type for which a
6479 -- predefined operator exists. If the operator yields a boolean type,
6480 -- the Operand_Type is implicitly referenced by the operator, and a
6481 -- reference to it must be generated.
6483 ---------------------------
6484 -- Add_Implicit_Operator --
6485 ---------------------------
6487 procedure Add_Implicit_Operator
6489 Op_Type : Entity_Id := Empty)
6491 Predef_Op : Entity_Id;
6494 Predef_Op := Current_Entity (Selector_Name (N));
6496 while Present (Predef_Op)
6497 and then Scope (Predef_Op) /= Standard_Standard
6499 Predef_Op := Homonym (Predef_Op);
6502 if Nkind (N) = N_Selected_Component then
6503 Change_Selected_Component_To_Expanded_Name (N);
6506 -- If the context is an unanalyzed function call, determine whether
6507 -- a binary or unary interpretation is required.
6509 if Nkind (Parent (N)) = N_Indexed_Component then
6511 Is_Binary_Call : constant Boolean :=
6513 (Next (First (Expressions (Parent (N)))));
6514 Is_Binary_Op : constant Boolean :=
6516 (Predef_Op) /= Last_Entity (Predef_Op);
6517 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
6520 if Is_Binary_Call then
6521 if Is_Binary_Op then
6522 Add_One_Interp (N, Predef_Op, T);
6524 Add_One_Interp (N, Predef_Op2, T);
6528 if not Is_Binary_Op then
6529 Add_One_Interp (N, Predef_Op, T);
6531 Add_One_Interp (N, Predef_Op2, T);
6537 Add_One_Interp (N, Predef_Op, T);
6539 -- For operators with unary and binary interpretations, if
6540 -- context is not a call, add both
6542 if Present (Homonym (Predef_Op)) then
6543 Add_One_Interp (N, Homonym (Predef_Op), T);
6547 -- The node is a reference to a predefined operator, and
6548 -- an implicit reference to the type of its operands.
6550 if Present (Op_Type) then
6551 Generate_Operator_Reference (N, Op_Type);
6553 Generate_Operator_Reference (N, T);
6555 end Add_Implicit_Operator;
6557 -- Start of processing for Has_Implicit_Operator
6560 if Ekind (P) = E_Package
6561 and then not In_Open_Scopes (P)
6563 Priv_Id := First_Private_Entity (P);
6566 Id := First_Entity (P);
6570 -- Boolean operators: an implicit declaration exists if the scope
6571 -- contains a declaration for a derived Boolean type, or for an
6572 -- array of Boolean type.
6574 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
6575 while Id /= Priv_Id loop
6576 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
6577 Add_Implicit_Operator (Id);
6584 -- Equality: look for any non-limited type (result is Boolean)
6586 when Name_Op_Eq | Name_Op_Ne =>
6587 while Id /= Priv_Id loop
6589 and then not Is_Limited_Type (Id)
6590 and then Is_Base_Type (Id)
6592 Add_Implicit_Operator (Standard_Boolean, Id);
6599 -- Comparison operators: scalar type, or array of scalar
6601 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
6602 while Id /= Priv_Id loop
6603 if (Is_Scalar_Type (Id)
6604 or else (Is_Array_Type (Id)
6605 and then Is_Scalar_Type (Component_Type (Id))))
6606 and then Is_Base_Type (Id)
6608 Add_Implicit_Operator (Standard_Boolean, Id);
6615 -- Arithmetic operators: any numeric type
6625 while Id /= Priv_Id loop
6626 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
6627 Add_Implicit_Operator (Id);
6634 -- Concatenation: any one-dimensional array type
6636 when Name_Op_Concat =>
6637 while Id /= Priv_Id loop
6638 if Is_Array_Type (Id)
6639 and then Number_Dimensions (Id) = 1
6640 and then Is_Base_Type (Id)
6642 Add_Implicit_Operator (Id);
6649 -- What is the others condition here? Should we be using a
6650 -- subtype of Name_Id that would restrict to operators ???
6652 when others => null;
6655 -- If we fall through, then we do not have an implicit operator
6659 end Has_Implicit_Operator;
6661 -----------------------------------
6662 -- Has_Loop_In_Inner_Open_Scopes --
6663 -----------------------------------
6665 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
6667 -- Several scope stacks are maintained by Scope_Stack. The base of the
6668 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6669 -- flag in the scope stack entry. Note that the scope stacks used to
6670 -- simply be delimited implicitly by the presence of Standard_Standard
6671 -- at their base, but there now are cases where this is not sufficient
6672 -- because Standard_Standard actually may appear in the middle of the
6673 -- active set of scopes.
6675 for J in reverse 0 .. Scope_Stack.Last loop
6677 -- S was reached without seing a loop scope first
6679 if Scope_Stack.Table (J).Entity = S then
6682 -- S was not yet reached, so it contains at least one inner loop
6684 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
6688 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6689 -- cases where Standard_Standard appears in the middle of the active
6690 -- set of scopes. This affects the declaration and overriding of
6691 -- private inherited operations in instantiations of generic child
6694 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
6697 raise Program_Error; -- unreachable
6698 end Has_Loop_In_Inner_Open_Scopes;
6700 --------------------
6701 -- In_Open_Scopes --
6702 --------------------
6704 function In_Open_Scopes (S : Entity_Id) return Boolean is
6706 -- Several scope stacks are maintained by Scope_Stack. The base of the
6707 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6708 -- flag in the scope stack entry. Note that the scope stacks used to
6709 -- simply be delimited implicitly by the presence of Standard_Standard
6710 -- at their base, but there now are cases where this is not sufficient
6711 -- because Standard_Standard actually may appear in the middle of the
6712 -- active set of scopes.
6714 for J in reverse 0 .. Scope_Stack.Last loop
6715 if Scope_Stack.Table (J).Entity = S then
6719 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6720 -- cases where Standard_Standard appears in the middle of the active
6721 -- set of scopes. This affects the declaration and overriding of
6722 -- private inherited operations in instantiations of generic child
6725 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6731 -----------------------------
6732 -- Inherit_Renamed_Profile --
6733 -----------------------------
6735 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6742 if Ekind (Old_S) = E_Operator then
6743 New_F := First_Formal (New_S);
6745 while Present (New_F) loop
6746 Set_Etype (New_F, Base_Type (Etype (New_F)));
6747 Next_Formal (New_F);
6750 Set_Etype (New_S, Base_Type (Etype (New_S)));
6753 New_F := First_Formal (New_S);
6754 Old_F := First_Formal (Old_S);
6756 while Present (New_F) loop
6757 New_T := Etype (New_F);
6758 Old_T := Etype (Old_F);
6760 -- If the new type is a renaming of the old one, as is the
6761 -- case for actuals in instances, retain its name, to simplify
6762 -- later disambiguation.
6764 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6765 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6766 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6770 Set_Etype (New_F, Old_T);
6773 Next_Formal (New_F);
6774 Next_Formal (Old_F);
6777 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
6778 Set_Etype (New_S, Etype (Old_S));
6781 end Inherit_Renamed_Profile;
6787 procedure Initialize is
6792 -------------------------
6793 -- Install_Use_Clauses --
6794 -------------------------
6796 procedure Install_Use_Clauses
6798 Force_Installation : Boolean := False)
6806 while Present (U) loop
6808 -- Case of USE package
6810 if Nkind (U) = N_Use_Package_Clause then
6811 P := First (Names (U));
6812 while Present (P) loop
6815 if Ekind (Id) = E_Package then
6817 Note_Redundant_Use (P);
6819 elsif Present (Renamed_Object (Id))
6820 and then In_Use (Renamed_Object (Id))
6822 Note_Redundant_Use (P);
6824 elsif Force_Installation or else Applicable_Use (P) then
6825 Use_One_Package (Id, U);
6836 P := First (Subtype_Marks (U));
6837 while Present (P) loop
6838 if not Is_Entity_Name (P)
6839 or else No (Entity (P))
6843 elsif Entity (P) /= Any_Type then
6851 Next_Use_Clause (U);
6853 end Install_Use_Clauses;
6855 -------------------------------------
6856 -- Is_Appropriate_For_Entry_Prefix --
6857 -------------------------------------
6859 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6860 P_Type : Entity_Id := T;
6863 if Is_Access_Type (P_Type) then
6864 P_Type := Designated_Type (P_Type);
6867 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6868 end Is_Appropriate_For_Entry_Prefix;
6870 -------------------------------
6871 -- Is_Appropriate_For_Record --
6872 -------------------------------
6874 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6876 function Has_Components (T1 : Entity_Id) return Boolean;
6877 -- Determine if given type has components (i.e. is either a record
6878 -- type or a type that has discriminants).
6880 --------------------
6881 -- Has_Components --
6882 --------------------
6884 function Has_Components (T1 : Entity_Id) return Boolean is
6886 return Is_Record_Type (T1)
6887 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6888 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6889 or else (Is_Incomplete_Type (T1)
6890 and then From_With_Type (T1)
6891 and then Present (Non_Limited_View (T1))
6892 and then Is_Record_Type
6893 (Get_Full_View (Non_Limited_View (T1))));
6896 -- Start of processing for Is_Appropriate_For_Record
6901 and then (Has_Components (T)
6902 or else (Is_Access_Type (T)
6903 and then Has_Components (Designated_Type (T))));
6904 end Is_Appropriate_For_Record;
6906 ------------------------
6907 -- Note_Redundant_Use --
6908 ------------------------
6910 procedure Note_Redundant_Use (Clause : Node_Id) is
6911 Pack_Name : constant Entity_Id := Entity (Clause);
6912 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6913 Decl : constant Node_Id := Parent (Clause);
6915 Prev_Use : Node_Id := Empty;
6916 Redundant : Node_Id := Empty;
6917 -- The Use_Clause which is actually redundant. In the simplest case it
6918 -- is Pack itself, but when we compile a body we install its context
6919 -- before that of its spec, in which case it is the use_clause in the
6920 -- spec that will appear to be redundant, and we want the warning to be
6921 -- placed on the body. Similar complications appear when the redundancy
6922 -- is between a child unit and one of its ancestors.
6925 Set_Redundant_Use (Clause, True);
6927 if not Comes_From_Source (Clause)
6929 or else not Warn_On_Redundant_Constructs
6934 if not Is_Compilation_Unit (Current_Scope) then
6936 -- If the use_clause is in an inner scope, it is made redundant by
6937 -- some clause in the current context, with one exception: If we're
6938 -- compiling a nested package body, and the use_clause comes from the
6939 -- corresponding spec, the clause is not necessarily fully redundant,
6940 -- so we should not warn. If a warning was warranted, it would have
6941 -- been given when the spec was processed.
6943 if Nkind (Parent (Decl)) = N_Package_Specification then
6945 Package_Spec_Entity : constant Entity_Id :=
6946 Defining_Unit_Name (Parent (Decl));
6948 if In_Package_Body (Package_Spec_Entity) then
6954 Redundant := Clause;
6955 Prev_Use := Cur_Use;
6957 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6959 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6960 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6964 if Cur_Unit = New_Unit then
6966 -- Redundant clause in same body
6968 Redundant := Clause;
6969 Prev_Use := Cur_Use;
6971 elsif Cur_Unit = Current_Sem_Unit then
6973 -- If the new clause is not in the current unit it has been
6974 -- analyzed first, and it makes the other one redundant.
6975 -- However, if the new clause appears in a subunit, Cur_Unit
6976 -- is still the parent, and in that case the redundant one
6977 -- is the one appearing in the subunit.
6979 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6980 Redundant := Clause;
6981 Prev_Use := Cur_Use;
6983 -- Most common case: redundant clause in body,
6984 -- original clause in spec. Current scope is spec entity.
6989 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6991 Redundant := Cur_Use;
6995 -- The new clause may appear in an unrelated unit, when
6996 -- the parents of a generic are being installed prior to
6997 -- instantiation. In this case there must be no warning.
6998 -- We detect this case by checking whether the current top
6999 -- of the stack is related to the current compilation.
7001 Scop := Current_Scope;
7002 while Present (Scop)
7003 and then Scop /= Standard_Standard
7005 if Is_Compilation_Unit (Scop)
7006 and then not Is_Child_Unit (Scop)
7010 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
7014 Scop := Scope (Scop);
7017 Redundant := Cur_Use;
7021 elsif New_Unit = Current_Sem_Unit then
7022 Redundant := Clause;
7023 Prev_Use := Cur_Use;
7026 -- Neither is the current unit, so they appear in parent or
7027 -- sibling units. Warning will be emitted elsewhere.
7033 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
7034 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
7036 -- Use_clause is in child unit of current unit, and the child unit
7037 -- appears in the context of the body of the parent, so it has been
7038 -- installed first, even though it is the redundant one. Depending on
7039 -- their placement in the context, the visible or the private parts
7040 -- of the two units, either might appear as redundant, but the
7041 -- message has to be on the current unit.
7043 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
7044 Redundant := Cur_Use;
7047 Redundant := Clause;
7048 Prev_Use := Cur_Use;
7051 -- If the new use clause appears in the private part of a parent unit
7052 -- it may appear to be redundant w.r.t. a use clause in a child unit,
7053 -- but the previous use clause was needed in the visible part of the
7054 -- child, and no warning should be emitted.
7056 if Nkind (Parent (Decl)) = N_Package_Specification
7058 List_Containing (Decl) = Private_Declarations (Parent (Decl))
7061 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
7062 Spec : constant Node_Id :=
7063 Specification (Unit (Cunit (Current_Sem_Unit)));
7066 if Is_Compilation_Unit (Par)
7067 and then Par /= Cunit_Entity (Current_Sem_Unit)
7068 and then Parent (Cur_Use) = Spec
7070 List_Containing (Cur_Use) = Visible_Declarations (Spec)
7077 -- Finally, if the current use clause is in the context then
7078 -- the clause is redundant when it is nested within the unit.
7080 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
7081 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
7082 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
7084 Redundant := Clause;
7085 Prev_Use := Cur_Use;
7091 if Present (Redundant) then
7092 Error_Msg_Sloc := Sloc (Prev_Use);
7093 Error_Msg_NE -- CODEFIX
7094 ("& is already use-visible through previous use clause #?",
7095 Redundant, Pack_Name);
7097 end Note_Redundant_Use;
7103 procedure Pop_Scope is
7104 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7105 S : constant Entity_Id := SST.Entity;
7108 if Debug_Flag_E then
7112 -- Set Default_Storage_Pool field of the library unit if necessary
7114 if Ekind_In (S, E_Package, E_Generic_Package)
7116 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
7119 Aux : constant Node_Id :=
7120 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
7122 if No (Default_Storage_Pool (Aux)) then
7123 Set_Default_Storage_Pool (Aux, Default_Pool);
7128 Scope_Suppress := SST.Save_Scope_Suppress;
7129 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
7130 Check_Policy_List := SST.Save_Check_Policy_List;
7131 Default_Pool := SST.Save_Default_Storage_Pool;
7133 if Debug_Flag_W then
7134 Write_Str ("<-- exiting scope: ");
7135 Write_Name (Chars (Current_Scope));
7136 Write_Str (", Depth=");
7137 Write_Int (Int (Scope_Stack.Last));
7141 End_Use_Clauses (SST.First_Use_Clause);
7143 -- If the actions to be wrapped are still there they will get lost
7144 -- causing incomplete code to be generated. It is better to abort in
7145 -- this case (and we do the abort even with assertions off since the
7146 -- penalty is incorrect code generation)
7148 if SST.Actions_To_Be_Wrapped_Before /= No_List
7150 SST.Actions_To_Be_Wrapped_After /= No_List
7152 raise Program_Error;
7155 -- Free last subprogram name if allocated, and pop scope
7157 Free (SST.Last_Subprogram_Name);
7158 Scope_Stack.Decrement_Last;
7165 procedure Push_Scope (S : Entity_Id) is
7166 E : constant Entity_Id := Scope (S);
7169 if Ekind (S) = E_Void then
7172 -- Set scope depth if not a non-concurrent type, and we have not yet set
7173 -- the scope depth. This means that we have the first occurrence of the
7174 -- scope, and this is where the depth is set.
7176 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
7177 and then not Scope_Depth_Set (S)
7179 if S = Standard_Standard then
7180 Set_Scope_Depth_Value (S, Uint_0);
7182 elsif Is_Child_Unit (S) then
7183 Set_Scope_Depth_Value (S, Uint_1);
7185 elsif not Is_Record_Type (Current_Scope) then
7186 if Ekind (S) = E_Loop then
7187 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
7189 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
7194 Scope_Stack.Increment_Last;
7197 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7201 SST.Save_Scope_Suppress := Scope_Suppress;
7202 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
7203 SST.Save_Check_Policy_List := Check_Policy_List;
7204 SST.Save_Default_Storage_Pool := Default_Pool;
7206 if Scope_Stack.Last > Scope_Stack.First then
7207 SST.Component_Alignment_Default := Scope_Stack.Table
7208 (Scope_Stack.Last - 1).
7209 Component_Alignment_Default;
7212 SST.Last_Subprogram_Name := null;
7213 SST.Is_Transient := False;
7214 SST.Node_To_Be_Wrapped := Empty;
7215 SST.Pending_Freeze_Actions := No_List;
7216 SST.Actions_To_Be_Wrapped_Before := No_List;
7217 SST.Actions_To_Be_Wrapped_After := No_List;
7218 SST.First_Use_Clause := Empty;
7219 SST.Is_Active_Stack_Base := False;
7220 SST.Previous_Visibility := False;
7223 if Debug_Flag_W then
7224 Write_Str ("--> new scope: ");
7225 Write_Name (Chars (Current_Scope));
7226 Write_Str (", Id=");
7227 Write_Int (Int (Current_Scope));
7228 Write_Str (", Depth=");
7229 Write_Int (Int (Scope_Stack.Last));
7233 -- Deal with copying flags from the previous scope to this one. This is
7234 -- not necessary if either scope is standard, or if the new scope is a
7237 if S /= Standard_Standard
7238 and then Scope (S) /= Standard_Standard
7239 and then not Is_Child_Unit (S)
7241 if Nkind (E) not in N_Entity then
7245 -- Copy categorization flags from Scope (S) to S, this is not done
7246 -- when Scope (S) is Standard_Standard since propagation is from
7247 -- library unit entity inwards. Copy other relevant attributes as
7248 -- well (Discard_Names in particular).
7250 -- We only propagate inwards for library level entities,
7251 -- inner level subprograms do not inherit the categorization.
7253 if Is_Library_Level_Entity (S) then
7254 Set_Is_Preelaborated (S, Is_Preelaborated (E));
7255 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
7256 Set_Discard_Names (S, Discard_Names (E));
7257 Set_Suppress_Value_Tracking_On_Call
7258 (S, Suppress_Value_Tracking_On_Call (E));
7259 Set_Categorization_From_Scope (E => S, Scop => E);
7263 if Is_Child_Unit (S)
7264 and then Present (E)
7265 and then Ekind_In (E, E_Package, E_Generic_Package)
7267 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
7270 Aux : constant Node_Id :=
7271 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
7273 if Present (Default_Storage_Pool (Aux)) then
7274 Default_Pool := Default_Storage_Pool (Aux);
7280 ---------------------
7281 -- Premature_Usage --
7282 ---------------------
7284 procedure Premature_Usage (N : Node_Id) is
7285 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
7286 E : Entity_Id := Entity (N);
7289 -- Within an instance, the analysis of the actual for a formal object
7290 -- does not see the name of the object itself. This is significant only
7291 -- if the object is an aggregate, where its analysis does not do any
7292 -- name resolution on component associations. (see 4717-008). In such a
7293 -- case, look for the visible homonym on the chain.
7296 and then Present (Homonym (E))
7301 and then not In_Open_Scopes (Scope (E))
7308 Set_Etype (N, Etype (E));
7313 if Kind = N_Component_Declaration then
7315 ("component&! cannot be used before end of record declaration", N);
7317 elsif Kind = N_Parameter_Specification then
7319 ("formal parameter&! cannot be used before end of specification",
7322 elsif Kind = N_Discriminant_Specification then
7324 ("discriminant&! cannot be used before end of discriminant part",
7327 elsif Kind = N_Procedure_Specification
7328 or else Kind = N_Function_Specification
7331 ("subprogram&! cannot be used before end of its declaration",
7334 elsif Kind = N_Full_Type_Declaration then
7336 ("type& cannot be used before end of its declaration!", N);
7340 ("object& cannot be used before end of its declaration!", N);
7342 end Premature_Usage;
7344 ------------------------
7345 -- Present_System_Aux --
7346 ------------------------
7348 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
7350 Aux_Name : Unit_Name_Type;
7351 Unum : Unit_Number_Type;
7356 function Find_System (C_Unit : Node_Id) return Entity_Id;
7357 -- Scan context clause of compilation unit to find with_clause
7364 function Find_System (C_Unit : Node_Id) return Entity_Id is
7365 With_Clause : Node_Id;
7368 With_Clause := First (Context_Items (C_Unit));
7369 while Present (With_Clause) loop
7370 if (Nkind (With_Clause) = N_With_Clause
7371 and then Chars (Name (With_Clause)) = Name_System)
7372 and then Comes_From_Source (With_Clause)
7383 -- Start of processing for Present_System_Aux
7386 -- The child unit may have been loaded and analyzed already
7388 if Present (System_Aux_Id) then
7391 -- If no previous pragma for System.Aux, nothing to load
7393 elsif No (System_Extend_Unit) then
7396 -- Use the unit name given in the pragma to retrieve the unit.
7397 -- Verify that System itself appears in the context clause of the
7398 -- current compilation. If System is not present, an error will
7399 -- have been reported already.
7402 With_Sys := Find_System (Cunit (Current_Sem_Unit));
7404 The_Unit := Unit (Cunit (Current_Sem_Unit));
7408 (Nkind (The_Unit) = N_Package_Body
7409 or else (Nkind (The_Unit) = N_Subprogram_Body
7411 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
7413 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
7417 and then Present (N)
7419 -- If we are compiling a subunit, we need to examine its
7420 -- context as well (Current_Sem_Unit is the parent unit);
7422 The_Unit := Parent (N);
7423 while Nkind (The_Unit) /= N_Compilation_Unit loop
7424 The_Unit := Parent (The_Unit);
7427 if Nkind (Unit (The_Unit)) = N_Subunit then
7428 With_Sys := Find_System (The_Unit);
7432 if No (With_Sys) then
7436 Loc := Sloc (With_Sys);
7437 Get_Name_String (Chars (Expression (System_Extend_Unit)));
7438 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
7439 Name_Buffer (1 .. 7) := "system.";
7440 Name_Buffer (Name_Len + 8) := '%';
7441 Name_Buffer (Name_Len + 9) := 's';
7442 Name_Len := Name_Len + 9;
7443 Aux_Name := Name_Find;
7447 (Load_Name => Aux_Name,
7450 Error_Node => With_Sys);
7452 if Unum /= No_Unit then
7453 Semantics (Cunit (Unum));
7455 Defining_Entity (Specification (Unit (Cunit (Unum))));
7458 Make_With_Clause (Loc,
7460 Make_Expanded_Name (Loc,
7461 Chars => Chars (System_Aux_Id),
7462 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
7463 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
7465 Set_Entity (Name (Withn), System_Aux_Id);
7467 Set_Library_Unit (Withn, Cunit (Unum));
7468 Set_Corresponding_Spec (Withn, System_Aux_Id);
7469 Set_First_Name (Withn, True);
7470 Set_Implicit_With (Withn, True);
7472 Insert_After (With_Sys, Withn);
7473 Mark_Rewrite_Insertion (Withn);
7474 Set_Context_Installed (Withn);
7478 -- Here if unit load failed
7481 Error_Msg_Name_1 := Name_System;
7482 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
7484 ("extension package `%.%` does not exist",
7485 Opt.System_Extend_Unit);
7489 end Present_System_Aux;
7491 -------------------------
7492 -- Restore_Scope_Stack --
7493 -------------------------
7495 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
7498 Comp_Unit : Node_Id;
7499 In_Child : Boolean := False;
7500 Full_Vis : Boolean := True;
7501 SS_Last : constant Int := Scope_Stack.Last;
7504 -- Restore visibility of previous scope stack, if any
7506 for J in reverse 0 .. Scope_Stack.Last loop
7507 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7508 or else No (Scope_Stack.Table (J).Entity);
7510 S := Scope_Stack.Table (J).Entity;
7512 if not Is_Hidden_Open_Scope (S) then
7514 -- If the parent scope is hidden, its entities are hidden as
7515 -- well, unless the entity is the instantiation currently
7518 if not Is_Hidden_Open_Scope (Scope (S))
7519 or else not Analyzed (Parent (S))
7520 or else Scope (S) = Standard_Standard
7522 Set_Is_Immediately_Visible (S, True);
7525 E := First_Entity (S);
7526 while Present (E) loop
7527 if Is_Child_Unit (E) then
7528 if not From_With_Type (E) then
7529 Set_Is_Immediately_Visible (E,
7530 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7534 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
7536 Nkind (Parent (Parent (E))) = N_Package_Specification);
7537 Set_Is_Immediately_Visible (E,
7538 Limited_View_Installed (Parent (Parent (E))));
7541 Set_Is_Immediately_Visible (E, True);
7547 and then Is_Package_Or_Generic_Package (S)
7549 -- We are in the visible part of the package scope
7551 exit when E = First_Private_Entity (S);
7555 -- The visibility of child units (siblings of current compilation)
7556 -- must be restored in any case. Their declarations may appear
7557 -- after the private part of the parent.
7559 if not Full_Vis then
7560 while Present (E) loop
7561 if Is_Child_Unit (E) then
7562 Set_Is_Immediately_Visible (E,
7563 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7571 if Is_Child_Unit (S)
7572 and not In_Child -- check only for current unit
7576 -- Restore visibility of parents according to whether the child
7577 -- is private and whether we are in its visible part.
7579 Comp_Unit := Parent (Unit_Declaration_Node (S));
7581 if Nkind (Comp_Unit) = N_Compilation_Unit
7582 and then Private_Present (Comp_Unit)
7586 elsif Is_Package_Or_Generic_Package (S)
7587 and then (In_Private_Part (S) or else In_Package_Body (S))
7591 -- if S is the scope of some instance (which has already been
7592 -- seen on the stack) it does not affect the visibility of
7595 elsif Is_Hidden_Open_Scope (S) then
7598 elsif (Ekind (S) = E_Procedure
7599 or else Ekind (S) = E_Function)
7600 and then Has_Completion (S)
7611 if SS_Last >= Scope_Stack.First
7612 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7615 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7617 end Restore_Scope_Stack;
7619 ----------------------
7620 -- Save_Scope_Stack --
7621 ----------------------
7623 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
7626 SS_Last : constant Int := Scope_Stack.Last;
7629 if SS_Last >= Scope_Stack.First
7630 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7633 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7636 -- If the call is from within a compilation unit, as when called from
7637 -- Rtsfind, make current entries in scope stack invisible while we
7638 -- analyze the new unit.
7640 for J in reverse 0 .. SS_Last loop
7641 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7642 or else No (Scope_Stack.Table (J).Entity);
7644 S := Scope_Stack.Table (J).Entity;
7645 Set_Is_Immediately_Visible (S, False);
7647 E := First_Entity (S);
7648 while Present (E) loop
7649 Set_Is_Immediately_Visible (E, False);
7655 end Save_Scope_Stack;
7661 procedure Set_Use (L : List_Id) is
7663 Pack_Name : Node_Id;
7670 while Present (Decl) loop
7671 if Nkind (Decl) = N_Use_Package_Clause then
7672 Chain_Use_Clause (Decl);
7674 Pack_Name := First (Names (Decl));
7675 while Present (Pack_Name) loop
7676 Pack := Entity (Pack_Name);
7678 if Ekind (Pack) = E_Package
7679 and then Applicable_Use (Pack_Name)
7681 Use_One_Package (Pack, Decl);
7687 elsif Nkind (Decl) = N_Use_Type_Clause then
7688 Chain_Use_Clause (Decl);
7690 Id := First (Subtype_Marks (Decl));
7691 while Present (Id) loop
7692 if Entity (Id) /= Any_Type then
7705 ---------------------
7706 -- Use_One_Package --
7707 ---------------------
7709 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
7712 Current_Instance : Entity_Id := Empty;
7714 Private_With_OK : Boolean := False;
7717 if Ekind (P) /= E_Package then
7722 Set_Current_Use_Clause (P, N);
7724 -- Ada 2005 (AI-50217): Check restriction
7726 if From_With_Type (P) then
7727 Error_Msg_N ("limited withed package cannot appear in use clause", N);
7730 -- Find enclosing instance, if any
7733 Current_Instance := Current_Scope;
7734 while not Is_Generic_Instance (Current_Instance) loop
7735 Current_Instance := Scope (Current_Instance);
7738 if No (Hidden_By_Use_Clause (N)) then
7739 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7743 -- If unit is a package renaming, indicate that the renamed
7744 -- package is also in use (the flags on both entities must
7745 -- remain consistent, and a subsequent use of either of them
7746 -- should be recognized as redundant).
7748 if Present (Renamed_Object (P)) then
7749 Set_In_Use (Renamed_Object (P));
7750 Set_Current_Use_Clause (Renamed_Object (P), N);
7751 Real_P := Renamed_Object (P);
7756 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7757 -- found in the private part of a package specification
7759 if In_Private_Part (Current_Scope)
7760 and then Has_Private_With (P)
7761 and then Is_Child_Unit (Current_Scope)
7762 and then Is_Child_Unit (P)
7763 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7765 Private_With_OK := True;
7768 -- Loop through entities in one package making them potentially
7771 Id := First_Entity (P);
7773 and then (Id /= First_Private_Entity (P)
7774 or else Private_With_OK) -- Ada 2005 (AI-262)
7776 Prev := Current_Entity (Id);
7777 while Present (Prev) loop
7778 if Is_Immediately_Visible (Prev)
7779 and then (not Is_Overloadable (Prev)
7780 or else not Is_Overloadable (Id)
7781 or else (Type_Conformant (Id, Prev)))
7783 if No (Current_Instance) then
7785 -- Potentially use-visible entity remains hidden
7787 goto Next_Usable_Entity;
7789 -- A use clause within an instance hides outer global entities,
7790 -- which are not used to resolve local entities in the
7791 -- instance. Note that the predefined entities in Standard
7792 -- could not have been hidden in the generic by a use clause,
7793 -- and therefore remain visible. Other compilation units whose
7794 -- entities appear in Standard must be hidden in an instance.
7796 -- To determine whether an entity is external to the instance
7797 -- we compare the scope depth of its scope with that of the
7798 -- current instance. However, a generic actual of a subprogram
7799 -- instance is declared in the wrapper package but will not be
7800 -- hidden by a use-visible entity. similarly, an entity that is
7801 -- declared in an enclosing instance will not be hidden by an
7802 -- an entity declared in a generic actual, which can only have
7803 -- been use-visible in the generic and will not have hidden the
7804 -- entity in the generic parent.
7806 -- If Id is called Standard, the predefined package with the
7807 -- same name is in the homonym chain. It has to be ignored
7808 -- because it has no defined scope (being the only entity in
7809 -- the system with this mandated behavior).
7811 elsif not Is_Hidden (Id)
7812 and then Present (Scope (Prev))
7813 and then not Is_Wrapper_Package (Scope (Prev))
7814 and then Scope_Depth (Scope (Prev)) <
7815 Scope_Depth (Current_Instance)
7816 and then (Scope (Prev) /= Standard_Standard
7817 or else Sloc (Prev) > Standard_Location)
7819 if In_Open_Scopes (Scope (Prev))
7820 and then Is_Generic_Instance (Scope (Prev))
7821 and then Present (Associated_Formal_Package (P))
7826 Set_Is_Potentially_Use_Visible (Id);
7827 Set_Is_Immediately_Visible (Prev, False);
7828 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7832 -- A user-defined operator is not use-visible if the predefined
7833 -- operator for the type is immediately visible, which is the case
7834 -- if the type of the operand is in an open scope. This does not
7835 -- apply to user-defined operators that have operands of different
7836 -- types, because the predefined mixed mode operations (multiply
7837 -- and divide) apply to universal types and do not hide anything.
7839 elsif Ekind (Prev) = E_Operator
7840 and then Operator_Matches_Spec (Prev, Id)
7841 and then In_Open_Scopes
7842 (Scope (Base_Type (Etype (First_Formal (Id)))))
7843 and then (No (Next_Formal (First_Formal (Id)))
7844 or else Etype (First_Formal (Id))
7845 = Etype (Next_Formal (First_Formal (Id)))
7846 or else Chars (Prev) = Name_Op_Expon)
7848 goto Next_Usable_Entity;
7850 -- In an instance, two homonyms may become use_visible through the
7851 -- actuals of distinct formal packages. In the generic, only the
7852 -- current one would have been visible, so make the other one
7855 elsif Present (Current_Instance)
7856 and then Is_Potentially_Use_Visible (Prev)
7857 and then not Is_Overloadable (Prev)
7858 and then Scope (Id) /= Scope (Prev)
7859 and then Used_As_Generic_Actual (Scope (Prev))
7860 and then Used_As_Generic_Actual (Scope (Id))
7861 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
7862 Current_Use_Clause (Scope (Id)))
7864 Set_Is_Potentially_Use_Visible (Prev, False);
7865 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7868 Prev := Homonym (Prev);
7871 -- On exit, we know entity is not hidden, unless it is private
7873 if not Is_Hidden (Id)
7874 and then ((not Is_Child_Unit (Id))
7875 or else Is_Visible_Child_Unit (Id))
7877 Set_Is_Potentially_Use_Visible (Id);
7879 if Is_Private_Type (Id)
7880 and then Present (Full_View (Id))
7882 Set_Is_Potentially_Use_Visible (Full_View (Id));
7886 <<Next_Usable_Entity>>
7890 -- Child units are also made use-visible by a use clause, but they may
7891 -- appear after all visible declarations in the parent entity list.
7893 while Present (Id) loop
7894 if Is_Child_Unit (Id)
7895 and then Is_Visible_Child_Unit (Id)
7897 Set_Is_Potentially_Use_Visible (Id);
7903 if Chars (Real_P) = Name_System
7904 and then Scope (Real_P) = Standard_Standard
7905 and then Present_System_Aux (N)
7907 Use_One_Package (System_Aux_Id, N);
7910 end Use_One_Package;
7916 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False) is
7918 Is_Known_Used : Boolean;
7922 function Spec_Reloaded_For_Body return Boolean;
7923 -- Determine whether the compilation unit is a package body and the use
7924 -- type clause is in the spec of the same package. Even though the spec
7925 -- was analyzed first, its context is reloaded when analysing the body.
7927 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
7928 -- AI05-150: if the use_type_clause carries the "all" qualifier,
7929 -- class-wide operations of ancestor types are use-visible if the
7930 -- ancestor type is visible.
7932 ----------------------------
7933 -- Spec_Reloaded_For_Body --
7934 ----------------------------
7936 function Spec_Reloaded_For_Body return Boolean is
7938 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7940 Spec : constant Node_Id :=
7941 Parent (List_Containing (Parent (Id)));
7944 Nkind (Spec) = N_Package_Specification
7945 and then Corresponding_Body (Parent (Spec)) =
7946 Cunit_Entity (Current_Sem_Unit);
7951 end Spec_Reloaded_For_Body;
7953 -------------------------------
7954 -- Use_Class_Wide_Operations --
7955 -------------------------------
7957 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
7961 function Is_Class_Wide_Operation_Of
7963 T : Entity_Id) return Boolean;
7964 -- Determine whether a subprogram has a class-wide parameter or
7965 -- result that is T'Class.
7967 ---------------------------------
7968 -- Is_Class_Wide_Operation_Of --
7969 ---------------------------------
7971 function Is_Class_Wide_Operation_Of
7973 T : Entity_Id) return Boolean
7978 Formal := First_Formal (Op);
7979 while Present (Formal) loop
7980 if Etype (Formal) = Class_Wide_Type (T) then
7983 Next_Formal (Formal);
7986 if Etype (Op) = Class_Wide_Type (T) then
7991 end Is_Class_Wide_Operation_Of;
7993 -- Start of processing for Use_Class_Wide_Operations
7996 Scop := Scope (Typ);
7997 if not Is_Hidden (Scop) then
7998 Ent := First_Entity (Scop);
7999 while Present (Ent) loop
8000 if Is_Overloadable (Ent)
8001 and then Is_Class_Wide_Operation_Of (Ent, Typ)
8002 and then not Is_Potentially_Use_Visible (Ent)
8004 Set_Is_Potentially_Use_Visible (Ent);
8005 Append_Elmt (Ent, Used_Operations (Parent (Id)));
8012 if Is_Derived_Type (Typ) then
8013 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
8015 end Use_Class_Wide_Operations;
8017 -- Start of processing for Use_One_Type;
8020 -- It is the type determined by the subtype mark (8.4(8)) whose
8021 -- operations become potentially use-visible.
8023 T := Base_Type (Entity (Id));
8025 -- Either the type itself is used, the package where it is declared
8026 -- is in use or the entity is declared in the current package, thus
8031 or else In_Use (Scope (T))
8032 or else Scope (T) = Current_Scope;
8034 Set_Redundant_Use (Id,
8035 Is_Known_Used or else Is_Potentially_Use_Visible (T));
8037 if Ekind (T) = E_Incomplete_Type then
8038 Error_Msg_N ("premature usage of incomplete type", Id);
8040 elsif In_Open_Scopes (Scope (T)) then
8043 -- A limited view cannot appear in a use_type clause. However, an access
8044 -- type whose designated type is limited has the flag but is not itself
8045 -- a limited view unless we only have a limited view of its enclosing
8048 elsif From_With_Type (T)
8049 and then From_With_Type (Scope (T))
8052 ("incomplete type from limited view "
8053 & "cannot appear in use clause", Id);
8055 -- If the subtype mark designates a subtype in a different package,
8056 -- we have to check that the parent type is visible, otherwise the
8057 -- use type clause is a noop. Not clear how to do that???
8059 elsif not Redundant_Use (Id) then
8062 -- If T is tagged, primitive operators on class-wide operands
8063 -- are also available.
8065 if Is_Tagged_Type (T) then
8066 Set_In_Use (Class_Wide_Type (T));
8069 Set_Current_Use_Clause (T, Parent (Id));
8071 -- Iterate over primitive operations of the type. If an operation is
8072 -- already use_visible, it is the result of a previous use_clause,
8073 -- and already appears on the corresponding entity chain. If the
8074 -- clause is being reinstalled, operations are already use-visible.
8080 Op_List := Collect_Primitive_Operations (T);
8081 Elmt := First_Elmt (Op_List);
8082 while Present (Elmt) loop
8083 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
8084 or else Chars (Node (Elmt)) in Any_Operator_Name)
8085 and then not Is_Hidden (Node (Elmt))
8086 and then not Is_Potentially_Use_Visible (Node (Elmt))
8088 Set_Is_Potentially_Use_Visible (Node (Elmt));
8089 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8091 elsif Ada_Version >= Ada_2012
8092 and then All_Present (Parent (Id))
8093 and then not Is_Hidden (Node (Elmt))
8094 and then not Is_Potentially_Use_Visible (Node (Elmt))
8096 Set_Is_Potentially_Use_Visible (Node (Elmt));
8097 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8104 if Ada_Version >= Ada_2012
8105 and then All_Present (Parent (Id))
8106 and then Is_Tagged_Type (T)
8108 Use_Class_Wide_Operations (T);
8112 -- If warning on redundant constructs, check for unnecessary WITH
8114 if Warn_On_Redundant_Constructs
8115 and then Is_Known_Used
8117 -- with P; with P; use P;
8118 -- package P is package X is package body X is
8119 -- type T ... use P.T;
8121 -- The compilation unit is the body of X. GNAT first compiles the
8122 -- spec of X, then proceeds to the body. At that point P is marked
8123 -- as use visible. The analysis then reinstalls the spec along with
8124 -- its context. The use clause P.T is now recognized as redundant,
8125 -- but in the wrong context. Do not emit a warning in such cases.
8126 -- Do not emit a warning either if we are in an instance, there is
8127 -- no redundancy between an outer use_clause and one that appears
8128 -- within the generic.
8130 and then not Spec_Reloaded_For_Body
8131 and then not In_Instance
8133 -- The type already has a use clause
8137 -- Case where we know the current use clause for the type
8139 if Present (Current_Use_Clause (T)) then
8140 Use_Clause_Known : declare
8141 Clause1 : constant Node_Id := Parent (Id);
8142 Clause2 : constant Node_Id := Current_Use_Clause (T);
8149 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
8150 -- Return the appropriate entity for determining which unit
8151 -- has a deeper scope: the defining entity for U, unless U
8152 -- is a package instance, in which case we retrieve the
8153 -- entity of the instance spec.
8155 --------------------
8156 -- Entity_Of_Unit --
8157 --------------------
8159 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
8161 if Nkind (U) = N_Package_Instantiation
8162 and then Analyzed (U)
8164 return Defining_Entity (Instance_Spec (U));
8166 return Defining_Entity (U);
8170 -- Start of processing for Use_Clause_Known
8173 -- If both current use type clause and the use type clause
8174 -- for the type are at the compilation unit level, one of
8175 -- the units must be an ancestor of the other, and the
8176 -- warning belongs on the descendant.
8178 if Nkind (Parent (Clause1)) = N_Compilation_Unit
8180 Nkind (Parent (Clause2)) = N_Compilation_Unit
8183 -- If the unit is a subprogram body that acts as spec,
8184 -- the context clause is shared with the constructed
8185 -- subprogram spec. Clearly there is no redundancy.
8187 if Clause1 = Clause2 then
8191 Unit1 := Unit (Parent (Clause1));
8192 Unit2 := Unit (Parent (Clause2));
8194 -- If both clauses are on same unit, or one is the body
8195 -- of the other, or one of them is in a subunit, report
8196 -- redundancy on the later one.
8198 if Unit1 = Unit2 then
8199 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8200 Error_Msg_NE -- CODEFIX
8201 ("& is already use-visible through previous "
8202 & "use_type_clause #?", Clause1, T);
8205 elsif Nkind (Unit1) = N_Subunit then
8206 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8207 Error_Msg_NE -- CODEFIX
8208 ("& is already use-visible through previous "
8209 & "use_type_clause #?", Clause1, T);
8212 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
8213 and then Nkind (Unit1) /= Nkind (Unit2)
8214 and then Nkind (Unit1) /= N_Subunit
8216 Error_Msg_Sloc := Sloc (Clause1);
8217 Error_Msg_NE -- CODEFIX
8218 ("& is already use-visible through previous "
8219 & "use_type_clause #?", Current_Use_Clause (T), T);
8223 -- There is a redundant use type clause in a child unit.
8224 -- Determine which of the units is more deeply nested.
8225 -- If a unit is a package instance, retrieve the entity
8226 -- and its scope from the instance spec.
8228 Ent1 := Entity_Of_Unit (Unit1);
8229 Ent2 := Entity_Of_Unit (Unit2);
8231 if Scope (Ent2) = Standard_Standard then
8232 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8235 elsif Scope (Ent1) = Standard_Standard then
8236 Error_Msg_Sloc := Sloc (Id);
8239 -- If both units are child units, we determine which one
8240 -- is the descendant by the scope distance to the
8241 -- ultimate parent unit.
8251 and then Present (S2)
8252 and then S1 /= Standard_Standard
8253 and then S2 /= Standard_Standard
8259 if S1 = Standard_Standard then
8260 Error_Msg_Sloc := Sloc (Id);
8263 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8269 Error_Msg_NE -- CODEFIX
8270 ("& is already use-visible through previous "
8271 & "use_type_clause #?", Err_No, Id);
8273 -- Case where current use type clause and the use type
8274 -- clause for the type are not both at the compilation unit
8275 -- level. In this case we don't have location information.
8278 Error_Msg_NE -- CODEFIX
8279 ("& is already use-visible through previous "
8280 & "use type clause?", Id, T);
8282 end Use_Clause_Known;
8284 -- Here if Current_Use_Clause is not set for T, another case
8285 -- where we do not have the location information available.
8288 Error_Msg_NE -- CODEFIX
8289 ("& is already use-visible through previous "
8290 & "use type clause?", Id, T);
8293 -- The package where T is declared is already used
8295 elsif In_Use (Scope (T)) then
8296 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
8297 Error_Msg_NE -- CODEFIX
8298 ("& is already use-visible through package use clause #?",
8301 -- The current scope is the package where T is declared
8304 Error_Msg_Node_2 := Scope (T);
8305 Error_Msg_NE -- CODEFIX
8306 ("& is already use-visible inside package &?", Id, T);
8315 procedure Write_Info is
8316 Id : Entity_Id := First_Entity (Current_Scope);
8319 -- No point in dumping standard entities
8321 if Current_Scope = Standard_Standard then
8325 Write_Str ("========================================================");
8327 Write_Str (" Defined Entities in ");
8328 Write_Name (Chars (Current_Scope));
8330 Write_Str ("========================================================");
8334 Write_Str ("-- none --");
8338 while Present (Id) loop
8339 Write_Entity_Info (Id, " ");
8344 if Scope (Current_Scope) = Standard_Standard then
8346 -- Print information on the current unit itself
8348 Write_Entity_Info (Current_Scope, " ");
8361 for J in reverse 1 .. Scope_Stack.Last loop
8362 S := Scope_Stack.Table (J).Entity;
8363 Write_Int (Int (S));
8364 Write_Str (" === ");
8365 Write_Name (Chars (S));
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